Job title: ML Systems Engineer - Model Training and Infrastructure (SWE-focused LLMs)
Location: London; full in-office working as default
Start date: ASAP
Compensation: £80,000 - £110,000 Base Salary & £80,000 - £110,000 Share options.
___________________________________________________________________________
Cosine is building autonomous AI engineers that plan, write and ship code inside real development workflows.
Our agents work across complex software systems, and our Lumen models are trained to do more than produce code that looks correct. They are built to understand existing architectures, follow established patterns and produce software that engineers can actually maintain.
We develop our agent tooling entirely in-house and post-train open-source models for reliable, enterprise-grade coding performance. Our products are designed for on-premise, VPC and fully air-gapped environments, including security-critical settings where control, privacy and robustness are non-negotiable.
In 2024, Cosine achieved a 72% score on OpenAI’s SWE-Lancer benchmark, placing us among the strongest real-world software-engineering AI systems evaluated.
We’re now looking for an ML Systems Engineer to help train the next generation of Lumen models.
This is a highly hands-on role at the intersection of machine learning, software engineering, data and infrastructure. You’ll build the environments in which models learn to write software, develop the pipelines that generate and curate training data, and run the fine-tuning and reinforcement-learning workloads that shape model behaviour.
If you’re excited by the idea that the future quality of coding agents will be determined not just by model architecture, but by the quality of their data, environments and reward functions, this is an opportunity to work directly on that problem.
___________________________________________________________________________
You’ll work closely with ML researchers, infrastructure engineers and product teams to decide:
What Lumen should learn next.
How to generate the right training data.
How to design environments that reflect real software-engineering work.
How to reward models for producing useful, maintainable code.
How to measure whether a new training run genuinely improves the experience for engineers.
The systems you build will sit directly inside our model-training loop. Models will write code, use tools, run tests and interact with real repositories. Your work will determine how those interactions are generated, evaluated and fed back into future training.
This is not a narrow research role and it is not traditional MLOps. You’ll move between custom PyTorch code, distributed data pipelines, Dockerised services, RL environments, evaluation infrastructure and production-quality software.
___________________________________________________________________________
Contribute to the end-to-end training of software-engineering models.
Implement supervised fine-tuning pipelines using curated code and conversation datasets.
Build reinforcement-learning loops in which models write code, run tests and use development tools.
Develop custom PyTorch dataloaders, training objectives and evaluation workflows.
Run and analyse fine-tuning and RL experiments across large, modern open-source models.
Develop synthetic data-generation pipelines for future RL and fine-tuning runs.
Design systems for producing, filtering, transforming and sampling large-scale datasets.
Work with object storage, dataset sharding and data-quality checks.
Investigate which examples, tasks and sampling strategies lead to better model behaviour.
Turn model failures into concrete improvements to training data and future experiments.
Design, build and deploy containerised services that support model training and evaluation.
Use Docker and orchestration platforms such as Kubernetes to operate RL infrastructure.
Build environments where agents can modify repositories, run tests, use tools and receive meaningful feedback.
Improve the reliability, reproducibility and observability of large-scale training runs.
Work across Python, Go and the surrounding infrastructure required to run these systems.
Help maintain and extend evaluation suites for code models.
Build evaluations around unit tests, benchmark suites, repository-level tasks and real engineering workflows.
Analyse model failure modes, reward-hacking risks and regressions.
Develop better ways to measure code quality, maintainability, correctness and architectural fit.
Feed evaluation results back into model, data and infrastructure decisions.
Work with research, infrastructure and product teams to identify the highest-value training problems.
Turn broad goals such as “make Lumen better at X” into clear experiments and measurable outcomes.
Develop opinionated reward functions for software-engineering agents.
Document decisions, communicate trade-offs and help the wider team understand what the results mean.
Take ownership of projects from initial idea through to deployment and iteration.
___________________________________________________________________________
You may come from software engineering, ML infrastructure, data engineering, applied machine learning or a closely related field.
You should be comfortable with:
Typically 3–5 years of experience, or equivalent evidence of strong technical ability.
Reading, debugging and writing non-trivial production code.
Working primarily in Python and Go.
Caring about correctness, maintainability and code quality as much as model metrics.
Taking ownership of ambiguous technical problems and turning them into working systems.
Practical experience with at least one of PyTorch, TensorFlow or JAX.
Implementing custom training loops, losses or dataloaders.
Understanding the relationship between data, objectives, evaluation and model behaviour.
A willingness to work close to the code rather than treating training infrastructure as a black box.
Experience with Docker and container-management or orchestration platforms such as Kubernetes.
Experience with at least one major cloud platform, such as GCP, AWS or Azure.
An understanding of how to build services that are reliable, observable and straightforward to operate.
Comfort working across application code, infrastructure and deployment systems.
Experience working with large-scale datasets and object storage.
Understanding of sharding, filtering, sampling and dataset versioning.
The judgement to recognise that data quality can matter as much as model architecture.
An interest in building data pipelines that are reproducible and useful for experimentation.
The ability to explain technical decisions and experimental results clearly.
Comfort documenting trade-offs and walking others through your reasoning.
A practical approach to deciding what to build, what to measure and what to leave out.
The curiosity to investigate failures rather than dismissing them as noise.
You do not need to have worked on every part of the stack. We care more about strong engineering fundamentals, technical judgement and the ability to learn quickly than about matching every keyword.
Nice to have
You don’t need all of these, but experience in the following areas would help you get up to speed quickly:
Synthetic data generation for code or language models.
Training LLMs in distributed environments.
Reinforcement learning, preference optimisation or reward modelling.
Data tooling such as SQL, Apache Iceberg or DuckDB.
LLM-as-a-judge systems or automated code evaluation.
Reward-hacking detection, robustness evaluation or safety-focused training.
Open-source contributions to LLM tooling, ML infrastructure or RL libraries.
Experience working with repository-level code tasks or software-engineering benchmarks.
___________________________________________________________________________
In your first few months, you will:
Become a trusted engineering partner to the research team.
Contribute to reliable data-generation, training and evaluation workflows.
Ship improvements to the infrastructure used in Lumen fine-tuning and RL runs.
Help identify why models fail on real software-engineering tasks.
Turn those failures into concrete changes to data, environments, reward functions or evaluation.
Build a strong understanding of the systems required to train capable SWE agents.
Longer term, you’ll help define how Cosine trains software-engineering models: what they learn, how they practise, what they are rewarded for and how we decide whether they are genuinely getting better.
___________________________________________________________________________
Coding agents are moving quickly, but producing plausible code is not the same as being a good software engineer.
The models we build need to work within existing codebases. They need to understand context, respect architectural decisions, write maintainable code, use tools effectively and recover when their first attempt fails.
That behaviour will not emerge from model scale alone. It will come from better environments, better data, better evaluations and better incentives.
You’ll work directly on all four.
Your contributions will influence the Lumen models used in Cosine’s self-serve and enterprise products, including deployments in organisations with demanding security and infrastructure requirements. You’ll have close proximity to the research, infrastructure and product decisions that determine where the system goes next.
This is a role for someone who wants to work on the full stack of modern model training, while staying grounded in the standards of production software engineering.
___________________________________________________________________________
Direct impact: Your work will shape the next generations of Lumen software-engineering models.
Real scale: Work with large open-source models, long context lengths and multi-node training runs.
Full-stack ML engineering: Move between PyTorch, distributed systems, data curation, RL infrastructure and MLOps.
Frontier problems: Help define how AI systems learn to perform real software-engineering work.
Meaningful ownership: Take ideas from vague training objective to deployed system and measurable result.
Close collaboration: Work alongside research, infrastructure, product and engineering in our Hoxton office.
We’re an in-office team, five days a week, by design. The problems we’re solving benefit from close collaboration, fast feedback and shared context.
If you want to help build AI systems that write software engineers can trust, this is an opportunity to work on one of the most important problems in the field.
Come help us build the future of software engineering.
___________________________________________________________________________
We value diverse backgrounds, perspectives, and ways of thinking, and we’re committed to creating an inclusive and respectful workplace.
We encourage applications from anyone who meets the role requirements, even if you don’t meet every single qualification. If you need reasonable adjustments at any stage of the hiring process, we’re happy to discuss them.
___________________________________________________________________________
We’re an in-office team, five days a week, by design. We believe the work we’re doing benefits from being together, collaborating closely, and building shared context.
What you can expect:
Competitive salary, benchmarked to the market
Equity / share options, so you share in the upside you help create
30 days’ holiday + bank holidays
Work hard in the office, collaborate closely, and switch off properly
Dog-friendly office - bring your dog to work
Weekly team breakfast & lunch
Monthly socials
Pension
High-quality equipment to do your best work
We care about focus, sustainability, and doing great work — not performative overwork. We value people who show up, contribute thoughtfully, collaborate well with their colleagues, and then go home.
This role won’t suit everyone. But if you want structure, clarity, strong collaboration, and a team that takes both the work and work-life balance seriously, it’s a great place to be.
___________________________________________________________________________
To comply with UK GDPR and our internal data-protection and equal-opportunity obligations, we only accept candidate applications and agency submissions via our Applicant Tracking System (ATS). This ensures appropriate privacy notices, lawful processing, auditability, and consistent retention controls.
Any CVs or candidate details received outside the ATS (including via email, Slack, or direct message) will be treated as unsolicited, will not be considered as part of the recruitment process, and will not give rise to any fee or payment obligation.
","descriptionPlain":"Job title: ML Systems Engineer - Model Training and Infrastructure (SWE-focused LLMs)\n\nLocation: London; full in-office working as default\n\nStart date: ASAP\n\nCompensation: £80,000 - £110,000 Base Salary & £80,000 - £110,000 Share options.\n\n___________________________________________________________________________\n\n\n\n\nHELP BUILD THE SOFTWARE ENGINEERS OF THE FUTURE\n\n\n\nCosine is building autonomous AI engineers that plan, write and ship code inside real development workflows.\n\nOur agents work across complex software systems, and our Lumen models are trained to do more than produce code that looks correct. They are built to understand existing architectures, follow established patterns and produce software that engineers can actually maintain.\n\nWe develop our agent tooling entirely in-house and post-train open-source models for reliable, enterprise-grade coding performance. Our products are designed for on-premise, VPC and fully air-gapped environments, including security-critical settings where control, privacy and robustness are non-negotiable.\n\nIn 2024, Cosine achieved a 72% score on OpenAI’s SWE-Lancer benchmark, placing us among the strongest real-world software-engineering AI systems evaluated.\n\nWe’re now looking for an ML Systems Engineer to help train the next generation of Lumen models.\n\nThis is a highly hands-on role at the intersection of machine learning, software engineering, data and infrastructure. You’ll build the environments in which models learn to write software, develop the pipelines that generate and curate training data, and run the fine-tuning and reinforcement-learning workloads that shape model behaviour.\n\nIf you’re excited by the idea that the future quality of coding agents will be determined not just by model architecture, but by the quality of their data, environments and reward functions, this is an opportunity to work directly on that problem.\n\n___________________________________________________________________________\n\n\n\n\nTHE ROLE\n\n\n\nYou’ll work closely with ML researchers, infrastructure engineers and product teams to decide:\n\n - What Lumen should learn next.\n\n - How to generate the right training data.\n\n - How to design environments that reflect real software-engineering work.\n\n - How to reward models for producing useful, maintainable code.\n\n - How to measure whether a new training run genuinely improves the experience for engineers.\n\nThe systems you build will sit directly inside our model-training loop. Models will write code, use tools, run tests and interact with real repositories. Your work will determine how those interactions are generated, evaluated and fed back into future training.\n\nThis is not a narrow research role and it is not traditional MLOps. You’ll move between custom PyTorch code, distributed data pipelines, Dockerised services, RL environments, evaluation infrastructure and production-quality software.\n\n___________________________________________________________________________\n\n\n\n\nWHAT YOU’LL DO\n\n\nBUILD THE TRAINING SYSTEMS BEHIND LUMEN\n\n - Contribute to the end-to-end training of software-engineering models.\n\n - Implement supervised fine-tuning pipelines using curated code and conversation datasets.\n\n - Build reinforcement-learning loops in which models write code, run tests and use development tools.\n\n - Develop custom PyTorch dataloaders, training objectives and evaluation workflows.\n\n - Run and analyse fine-tuning and RL experiments across large, modern open-source models.\n\n\nCREATE THE DATA THAT TEACHES MODELS TO ENGINEER\n\n - Develop synthetic data-generation pipelines for future RL and fine-tuning runs.\n\n - Design systems for producing, filtering, transforming and sampling large-scale datasets.\n\n - Work with object storage, dataset sharding and data-quality checks.\n\n - Investigate which examples, tasks and sampling strategies lead to better model behaviour.\n\n - Turn model failures into concrete improvements to training data and future experiments.\n\n\nBUILD RELIABLE RL INFRASTRUCTURE\n\n - Design, build and deploy containerised services that support model training and evaluation.\n\n - Use Docker and orchestration platforms such as Kubernetes to operate RL infrastructure.\n\n - Build environments where agents can modify repositories, run tests, use tools and receive meaningful feedback.\n\n - Improve the reliability, reproducibility and observability of large-scale training runs.\n\n - Work across Python, Go and the surrounding infrastructure required to run these systems.\n\n\nIMPROVE HOW WE EVALUATE SWE MODELS\n\n - Help maintain and extend evaluation suites for code models.\n\n - Build evaluations around unit tests, benchmark suites, repository-level tasks and real engineering workflows.\n\n - Analyse model failure modes, reward-hacking risks and regressions.\n\n - Develop better ways to measure code quality, maintainability, correctness and architectural fit.\n\n - Feed evaluation results back into model, data and infrastructure decisions.\n\n\nSHAPE THE NEXT TRAINING DIRECTION\n\n - Work with research, infrastructure and product teams to identify the highest-value training problems.\n\n - Turn broad goals such as “make Lumen better at X” into clear experiments and measurable outcomes.\n\n - Develop opinionated reward functions for software-engineering agents.\n\n - Document decisions, communicate trade-offs and help the wider team understand what the results mean.\n\n - Take ownership of projects from initial idea through to deployment and iteration.\n\n___________________________________________________________________________\n\n\n\n\nWHAT WE’RE LOOKING FOR\n\nYou may come from software engineering, ML infrastructure, data engineering, applied machine learning or a closely related field.\n\nYou should be comfortable with:\n\n\nSTRONG SOFTWARE ENGINEERING FUNDAMENTALS\n\n - Typically 3–5 years of experience, or equivalent evidence of strong technical ability.\n\n - Reading, debugging and writing non-trivial production code.\n\n - Working primarily in Python and Go.\n\n - Caring about correctness, maintainability and code quality as much as model metrics.\n\n - Taking ownership of ambiguous technical problems and turning them into working systems.\n\n\nTRAINING FRAMEWORKS AND ML SYSTEMS\n\n - Practical experience with at least one of PyTorch, TensorFlow or JAX.\n\n - Implementing custom training loops, losses or dataloaders.\n\n - Understanding the relationship between data, objectives, evaluation and model behaviour.\n\n - A willingness to work close to the code rather than treating training infrastructure as a black box.\n\n\nCONTAINERS AND CLOUD INFRASTRUCTURE\n\n - Experience with Docker and container-management or orchestration platforms such as Kubernetes.\n\n - Experience with at least one major cloud platform, such as GCP, AWS or Azure.\n\n - An understanding of how to build services that are reliable, observable and straightforward to operate.\n\n - Comfort working across application code, infrastructure and deployment systems.\n\n\nDATA ENGINEERING INSTINCTS\n\n - Experience working with large-scale datasets and object storage.\n\n - Understanding of sharding, filtering, sampling and dataset versioning.\n\n - The judgement to recognise that data quality can matter as much as model architecture.\n\n - An interest in building data pipelines that are reproducible and useful for experimentation.\n\n\nCLEAR COMMUNICATION AND OWNERSHIP\n\n - The ability to explain technical decisions and experimental results clearly.\n\n - Comfort documenting trade-offs and walking others through your reasoning.\n\n - A practical approach to deciding what to build, what to measure and what to leave out.\n\n - The curiosity to investigate failures rather than dismissing them as noise.\n\nYou do not need to have worked on every part of the stack. We care more about strong engineering fundamentals, technical judgement and the ability to learn quickly than about matching every keyword.\n\n\n\nNice to have\n\nYou don’t need all of these, but experience in the following areas would help you get up to speed quickly:\n\n - Synthetic data generation for code or language models.\n\n - Training LLMs in distributed environments.\n\n - Reinforcement learning, preference optimisation or reward modelling.\n\n - Data tooling such as SQL, Apache Iceberg or DuckDB.\n\n - LLM-as-a-judge systems or automated code evaluation.\n\n - Reward-hacking detection, robustness evaluation or safety-focused training.\n\n - Open-source contributions to LLM tooling, ML infrastructure or RL libraries.\n\n - Experience working with repository-level code tasks or software-engineering benchmarks.\n\n___________________________________________________________________________\n\n\n\n\nWHAT SUCCESS LOOKS LIKE\n\nIn your first few months, you will:\n\n - Become a trusted engineering partner to the research team.\n\n - Contribute to reliable data-generation, training and evaluation workflows.\n\n - Ship improvements to the infrastructure used in Lumen fine-tuning and RL runs.\n\n - Help identify why models fail on real software-engineering tasks.\n\n - Turn those failures into concrete changes to data, environments, reward functions or evaluation.\n\n - Build a strong understanding of the systems required to train capable SWE agents.\n\nLonger term, you’ll help define how Cosine trains software-engineering models: what they learn, how they practise, what they are rewarded for and how we decide whether they are genuinely getting better.\n\n___________________________________________________________________________\n\n\n\n\nWHY THIS ROLE MATTERS\n\nCoding agents are moving quickly, but producing plausible code is not the same as being a good software engineer.\n\nThe models we build need to work within existing codebases. They need to understand context, respect architectural decisions, write maintainable code, use tools effectively and recover when their first attempt fails.\n\nThat behaviour will not emerge from model scale alone. It will come from better environments, better data, better evaluations and better incentives.\n\nYou’ll work directly on all four.\n\nYour contributions will influence the Lumen models used in Cosine’s self-serve and enterprise products, including deployments in organisations with demanding security and infrastructure requirements. You’ll have close proximity to the research, infrastructure and product decisions that determine where the system goes next.\n\nThis is a role for someone who wants to work on the full stack of modern model training, while staying grounded in the standards of production software engineering.\n\n___________________________________________________________________________\n\n\n\n\nWHY JOIN COSINE\n\n - Direct impact: Your work will shape the next generations of Lumen software-engineering models.\n\n - Real scale: Work with large open-source models, long context lengths and multi-node training runs.\n\n - Full-stack ML engineering: Move between PyTorch, distributed systems, data curation, RL infrastructure and MLOps.\n\n - Frontier problems: Help define how AI systems learn to perform real software-engineering work.\n\n - Meaningful ownership: Take ideas from vague training objective to deployed system and measurable result.\n\n - Close collaboration: Work alongside research, infrastructure, product and engineering in our Hoxton office.\n\nWe’re an in-office team, five days a week, by design. The problems we’re solving benefit from close collaboration, fast feedback and shared context.\n\nIf you want to help build AI systems that write software engineers can trust, this is an opportunity to work on one of the most important problems in the field.\n\nCome help us build the future of software engineering.\n\n___________________________________________________________________________\n\n\n\nCOSINE IS AN EQUAL OPPORTUNITY EMPLOYER.\n\n\nWe value diverse backgrounds, perspectives, and ways of thinking, and we’re committed to creating an inclusive and respectful workplace.\n\nWe encourage applications from anyone who meets the role requirements, even if you don’t meet every single qualification. If you need reasonable adjustments at any stage of the hiring process, we’re happy to discuss them.\n\n___________________________________________________________________________\n\n\n\n\nCOMPENSATION, BENEFITS & WAYS OF WORKING\n\nWe’re an in-office team, five days a week, by design. We believe the work we’re doing benefits from being together, collaborating closely, and building shared context.\n\n\n\nWhat you can expect:\n\n - Competitive salary, benchmarked to the market\n\n - Equity / share options, so you share in the upside you help create\n\n - 30 days’ holiday + bank holidays\n\n - Work hard in the office, collaborate closely, and switch off properly\n\n - Dog-friendly office - bring your dog to work\n\n - Weekly team breakfast & lunch\n\n - Monthly socials\n\n - Pension\n\n - High-quality equipment to do your best work\n\nWe care about focus, sustainability, and doing great work — not performative overwork. We value people who show up, contribute thoughtfully, collaborate well with their colleagues, and then go home.\n\nThis role won’t suit everyone. But if you want structure, clarity, strong collaboration, and a team that takes both the work and work-life balance seriously, it’s a great place to be.\n\n___________________________________________________________________________\n\n\n\n\nAGENCY & DATA PROTECTION NOTICE\n\nTo comply with UK GDPR and our internal data-protection and equal-opportunity obligations, we only accept candidate applications and agency submissions via our Applicant Tracking System (ATS). This ensures appropriate privacy notices, lawful processing, auditability, and consistent retention controls.\n\nAny CVs or candidate details received outside the ATS (including via email, Slack, or direct message) will be treated as unsolicited, will not be considered as part of the recruitment process, and will not give rise to any fee or payment obligation."},{"id":"1c4aef01-61ee-40ba-b919-f77a244b3847","title":"Forward Deployed Product Engineer","department":"Product & Engineering","team":"Product & Engineering","employmentType":"FullTime","location":"London Office","secondaryLocations":[],"publishedAt":"2026-05-14T16:03:54.438+00:00","isListed":true,"isRemote":false,"workplaceType":"OnSite","address":{"postalAddress":{"addressRegion":"England","addressCountry":"United Kingdom","addressLocality":"London"}},"jobUrl":"https://jobs.ashbyhq.com/cosine/1c4aef01-61ee-40ba-b919-f77a244b3847","applyUrl":"https://jobs.ashbyhq.com/cosine/1c4aef01-61ee-40ba-b919-f77a244b3847/application","descriptionHtml":"Job Title: Forward Deployed Product Engineer
Location: London; full in-office working as default
Start date: ASAP
Reports to: Head of Engineering
Compensation: £100,000 - £120,000 + EQUITY
___________________________________________________________________________
Cosine is the UK's frontier AI lab for autonomous software engineering — not another coding assistant, but our own models, agent stack, eval harnesses, and product layer. We build our agent tooling entirely in-house and post-train open-source models to deliver reliable, enterprise-grade coding performance in security-critical settings.
Our offerings can be used as SaaS, deployed on VPC, on-prem or fully air-gapped. Through this flexability, we are able to service large-scale, highly regulated enterprises and industries including defence, financial service and healthcare.
We’re backed by YC and were recently selected for the UK’s sovereign AI programme. The company is at a rare stage: deep technical work, real enterprise pull, and a chance to shape how AI is deployed inside defence, banking, government, and other high-trust environments.
This role is based in our Hoxton office, five days a week, because close collaboration, fast feedback, and shared context matter for the problems we’re solving.
___________________________________________________________________________
A Forward Deployed Product Engineer at Cosine works directly with customers and closely across research, engineering, infrastructure, product, and design to turn advanced AI capabilities into intuitive, reliable tools for developers, and deploy them successfully in complex customer environments.
You will be responsible for building and evolving Cosine’s user-facing product surfaces, including dedicated apps and web applications that expose the power of our models through well-designed workflows and interfaces. Your work sits at the intersection of product, platform, and research, translating emerging model capabilities into concrete experiences developers can use every day.
You will work directly with customers to assess their needs, understand their workflows and technical constraints, and design and help implement solutions that meet those needs. You will take ownership of deploying, integrating, and troubleshooting Cosine in complex, security-critical environments, bringing what you learn back into the core product. Hands-on full-stack product development is a central part of the role.
We focus on rapid product iteration without compromising quality. This means building systems that are performant, observable, and robust, while remaining flexible enough to evolve alongside fast-moving research and user needs. You will help define how developers interact with Cosine, from first use through advanced, production-grade workflows.
___________________________________________________________________________
Push the boundaries of what an autonomous agentic AI engineer can do by building scalable, high-quality web application interfaces and integrations that expose the power of our models in intuitive, reliable ways, and working directly with customers to deploy solutions that meet their needs in complex environments.
Build end-user products (command line interfaces, web applications and platform capabilities) that integrate with the Cosine platform APIs
Work directly with customers to assess their needs, workflows, infrastructure, and security constraints, and translate these into solution designs and implementation plans
Own the technical delivery of customer solutions, from deployment and integration with existing systems through troubleshooting and reliable production use
Diagnose and resolve issues across application code, APIs, infrastructure, and customer environments, collaborating with customer teams and internal specialists
Feed customer requirements and deployment learnings back into reusable product features and integrations
Enable developers to use advanced language models to augment their workflows and problem-solving capabilities
Collaborate closely research to explore and validate new product experiences and capabilities
Translate emerging model capabilities into concrete, user-facing features
Maintain a high bar for performance, reliability, and usability across platforms
Be opinionated about and bring your own ideas to the table, we’re building for engineers, as an engineer you have a say in what you want to use.
___________________________________________________________________________
Forward Deployed Engineering & Customer Delivery
Prior experience as a Forward Deployed Engineer is required
Must hold current security clearance
Experience working directly with customers to assess their needs and translate business requirements, technical constraints, and security requirements into practical solution designs
Hands-on experience deploying, integrating, and troubleshooting software in complex customer environments
Ability to own technical delivery from discovery and solution design through implementation and production support
Strong communication skills, with the ability to work effectively with technical and non-technical customer stakeholders
Frontend & Application Development
Experience building reactive, highly interactive applications (React, Svelte, Vue)
Experience with cli application development or local software development is a plus
Backend & Systems
Experience with backend development
Experience designing and consuming REST APIs
Developer Experience
Experience working with developer tooling
Familiarity with CI/CD pipelines
Experience with containerization
Programming Languages
Strong experience with TypeScript and modern frontend frameworks
Knowledge of Node.js, Python, and Go is a plus
Tooling & Infrastructure
Git, Docker, Webpack, npm, Kubernetes, GCP
Monitoring and alerting tools (e.g. Grafana, Datadog)
Feature flagging systems
___________________________________________________________________________
Have 5+ years of experience building production-grade software.
Have shipped and maintained complex frontend or full-stack applications used by technical users.
Are comfortable building highly interactive web or IDE-based experiences using modern frameworks (e.g. React, TypeScript).
Have experience designing and consuming APIs, and understand how frontend and backend systems evolve together.
Enjoy working directly with customers, understanding their needs, and taking responsibility for making solutions work in their environments.
Are comfortable moving between hands-on full-stack product development, customer-facing solution design, and deployment troubleshooting.
Enjoy working close to the product surface, translating ambiguous ideas and model capabilities into intuitive developer workflows.
Care deeply about developer experience, performance, and reliability - not just functionality.
Are comfortable iterating quickly, running experiments, and refining products based on real user feedback.
Can operate effectively in a fast-moving environment with evolving priorities and incomplete information.
___________________________________________________________________________
We value diverse backgrounds, perspectives, and ways of thinking, and we’re committed to creating an inclusive and respectful workplace.
We encourage applications from anyone who meets the role requirements, even if you don’t meet every single qualification. If you need reasonable adjustments at any stage of the hiring process, we’re happy to discuss them.
___________________________________________________________________________
We’re an in-office team, five days a week, by design. We believe the work we’re doing benefits from being together, collaborating closely, and building shared context.
What you can expect:
Competitive salary, benchmarked to the market
Equity / share options, so you share in the upside you help create
30 days’ holiday + bank holidays
Work hard in the office, collaborate closely, and switch off properly
Dog-friendly office - bring your dog to work
Weekly team breakfast & lunch
Monthly socials
Pension
High-quality equipment to do your best work
We care about focus, sustainability, and doing great work - not performative overwork. We value people who show up, contribute thoughtfully, collaborate well with their colleagues, and then go home.
This role won’t suit everyone. But if you want structure, clarity, strong collaboration, and a team that takes both the work and work-life balance seriously, it’s a great place to be.
___________________________________________________________________________
To comply with UK GDPR and our internal data-protection and equal-opportunity obligations, we only accept candidate applications and agency submissions via our Applicant Tracking System (ATS). This ensures appropriate privacy notices, lawful processing, auditability, and consistent retention controls.
Any CVs or candidate details received outside the ATS (including via email, Slack, or direct message) will be treated as unsolicited, will not be considered as part of the recruitment process, and will not give rise to any fee or payment obligation.
","descriptionPlain":"Job Title: Forward Deployed Product Engineer\nLocation: London; full in-office working as default\nStart date: ASAP\nReports to: Head of Engineering\nCompensation: £100,000 - £120,000 + EQUITY\n\n___________________________________________________________________________\n\n\n\n\nCOSINE AT A GLANCE\n\n\n\nCosine is the UK's frontier AI lab for autonomous software engineering — not another coding assistant, but our own models, agent stack, eval harnesses, and product layer. We build our agent tooling entirely in-house and post-train open-source models to deliver reliable, enterprise-grade coding performance in security-critical settings.\n\nOur offerings can be used as SaaS, deployed on VPC, on-prem or fully air-gapped. Through this flexability, we are able to service large-scale, highly regulated enterprises and industries including defence, financial service and healthcare.\n\nWe’re backed by YC and were recently selected for the UK’s sovereign AI programme. The company is at a rare stage: deep technical work, real enterprise pull, and a chance to shape how AI is deployed inside defence, banking, government, and other high-trust environments.\n\nThis role is based in our Hoxton office, five days a week, because close collaboration, fast feedback, and shared context matter for the problems we’re solving.\n\n\n\n___________________________________________________________________________\n\n\n\n\nTHE ROLE\n\n\n\nA Forward Deployed Product Engineer at Cosine works directly with customers and closely across research, engineering, infrastructure, product, and design to turn advanced AI capabilities into intuitive, reliable tools for developers, and deploy them successfully in complex customer environments.\n\nYou will be responsible for building and evolving Cosine’s user-facing product surfaces, including dedicated apps and web applications that expose the power of our models through well-designed workflows and interfaces. Your work sits at the intersection of product, platform, and research, translating emerging model capabilities into concrete experiences developers can use every day.\n\nYou will work directly with customers to assess their needs, understand their workflows and technical constraints, and design and help implement solutions that meet those needs. You will take ownership of deploying, integrating, and troubleshooting Cosine in complex, security-critical environments, bringing what you learn back into the core product. Hands-on full-stack product development is a central part of the role.\n\nWe focus on rapid product iteration without compromising quality. This means building systems that are performant, observable, and robust, while remaining flexible enough to evolve alongside fast-moving research and user needs. You will help define how developers interact with Cosine, from first use through advanced, production-grade workflows.\n\n\n\n___________________________________________________________________________\n\n\n\n\nYOUR MISSION\n\n\n\nPush the boundaries of what an autonomous agentic AI engineer can do by building scalable, high-quality web application interfaces and integrations that expose the power of our models in intuitive, reliable ways, and working directly with customers to deploy solutions that meet their needs in complex environments.\n\n\n\n\nRESPONSIBILITIES\n\n - Build end-user products (command line interfaces, web applications and platform capabilities) that integrate with the Cosine platform APIs\n\n - Work directly with customers to assess their needs, workflows, infrastructure, and security constraints, and translate these into solution designs and implementation plans\n\n - Own the technical delivery of customer solutions, from deployment and integration with existing systems through troubleshooting and reliable production use\n\n - Diagnose and resolve issues across application code, APIs, infrastructure, and customer environments, collaborating with customer teams and internal specialists\n\n - Feed customer requirements and deployment learnings back into reusable product features and integrations\n\n - Enable developers to use advanced language models to augment their workflows and problem-solving capabilities\n\n - Collaborate closely research to explore and validate new product experiences and capabilities\n\n - Translate emerging model capabilities into concrete, user-facing features\n\n - Maintain a high bar for performance, reliability, and usability across platforms\n\n - Be opinionated about and bring your own ideas to the table, we’re building for engineers, as an engineer you have a say in what you want to use.\n \n ___________________________________________________________________________\n\n\n\n\nSKILLS & EXPERIENCE\n\nForward Deployed Engineering & Customer Delivery\n\n - Prior experience as a Forward Deployed Engineer is required\n\n - Must hold current security clearance\n\n - Experience working directly with customers to assess their needs and translate business requirements, technical constraints, and security requirements into practical solution designs\n\n - Hands-on experience deploying, integrating, and troubleshooting software in complex customer environments\n\n - Ability to own technical delivery from discovery and solution design through implementation and production support\n\n - Strong communication skills, with the ability to work effectively with technical and non-technical customer stakeholders\n\nFrontend & Application Development\n\n - Experience building reactive, highly interactive applications (React, Svelte, Vue)\n\n - Experience with cli application development or local software development is a plus\n\nBackend & Systems\n\n - Experience with backend development\n\n - Experience designing and consuming REST APIs\n\nDeveloper Experience\n\n - Experience working with developer tooling\n\n - Familiarity with CI/CD pipelines\n\n - Experience with containerization\n\nProgramming Languages\n\n - Strong experience with TypeScript and modern frontend frameworks\n\n - Knowledge of Node.js, Python, and Go is a plus\n\nTooling & Infrastructure\n\n - Git, Docker, Webpack, npm, Kubernetes, GCP\n\n - Monitoring and alerting tools (e.g. Grafana, Datadog)\n\n - Feature flagging systems\n\n___________________________________________________________________________\n\n\n\n\n\n\n\nYOU MIGHT THRIVE IN THIS ROLE IF YOU:\n\n - Have 5+ years of experience building production-grade software.\n\n - Have shipped and maintained complex frontend or full-stack applications used by technical users.\n\n - Are comfortable building highly interactive web or IDE-based experiences using modern frameworks (e.g. React, TypeScript).\n\n - Have experience designing and consuming APIs, and understand how frontend and backend systems evolve together.\n\n - Enjoy working directly with customers, understanding their needs, and taking responsibility for making solutions work in their environments.\n\n - Are comfortable moving between hands-on full-stack product development, customer-facing solution design, and deployment troubleshooting.\n\n - Enjoy working close to the product surface, translating ambiguous ideas and model capabilities into intuitive developer workflows.\n\n - Care deeply about developer experience, performance, and reliability - not just functionality.\n\n - Are comfortable iterating quickly, running experiments, and refining products based on real user feedback.\n\n - Can operate effectively in a fast-moving environment with evolving priorities and incomplete information.\n\n___________________________________________________________________________\n\n\n\n\n\nCOSINE IS AN EQUAL OPPORTUNITY EMPLOYER.\n\n\nWe value diverse backgrounds, perspectives, and ways of thinking, and we’re committed to creating an inclusive and respectful workplace.\n\nWe encourage applications from anyone who meets the role requirements, even if you don’t meet every single qualification. If you need reasonable adjustments at any stage of the hiring process, we’re happy to discuss them.\n\n\n\n___________________________________________________________________________\n\n\n\n\nCOMPENSATION, BENEFITS & WAYS OF WORKING\n\nWe’re an in-office team, five days a week, by design. We believe the work we’re doing benefits from being together, collaborating closely, and building shared context.\n\n\n\nWhat you can expect:\n\n - Competitive salary, benchmarked to the market\n\n - Equity / share options, so you share in the upside you help create\n\n - 30 days’ holiday + bank holidays\n\n - Work hard in the office, collaborate closely, and switch off properly\n\n - Dog-friendly office - bring your dog to work\n\n - Weekly team breakfast & lunch\n\n - Monthly socials\n\n - Pension\n\n - High-quality equipment to do your best work\n\nWe care about focus, sustainability, and doing great work - not performative overwork. We value people who show up, contribute thoughtfully, collaborate well with their colleagues, and then go home.\n\nThis role won’t suit everyone. But if you want structure, clarity, strong collaboration, and a team that takes both the work and work-life balance seriously, it’s a great place to be.\n\n\n\n___________________________________________________________________________\n\n\n\n\nAGENCY & DATA PROTECTION NOTICE\n\nTo comply with UK GDPR and our internal data-protection and equal-opportunity obligations, we only accept candidate applications and agency submissions via our Applicant Tracking System (ATS). This ensures appropriate privacy notices, lawful processing, auditability, and consistent retention controls.\n\nAny CVs or candidate details received outside the ATS (including via email, Slack, or direct message) will be treated as unsolicited, will not be considered as part of the recruitment process, and will not give rise to any fee or payment obligation."},{"id":"0f8d2187-d6f8-4ff9-9680-96c849529b05","title":"Technical GTM Lead","department":"GTM","team":"GTM","employmentType":"FullTime","location":"London Office","secondaryLocations":[],"publishedAt":"2026-10-09T11:06:08.997+00:00","isListed":true,"isRemote":false,"workplaceType":"OnSite","address":{"postalAddress":{"addressRegion":"England","addressCountry":"United Kingdom","addressLocality":"London"}},"jobUrl":"https://jobs.ashbyhq.com/cosine/0f8d2187-d6f8-4ff9-9680-96c849529b05","applyUrl":"https://jobs.ashbyhq.com/cosine/0f8d2187-d6f8-4ff9-9680-96c849529b05/application","descriptionHtml":"Job title: Technical GTM Lead
Location: London; full in-office working as default
Start date: ASAP
Reports to: CRO
Compensation: Salary and Equity options available for discussion
Application deadline: 01/11/26 at 23:59 UK time
___________________________________________________________________________
Cosine is a UK AI lab building models, applications and training infrastructure for mission-critical organisations.
We build coding agents that work across real software systems, specialised Lumen models, AI-native security products and the infrastructure needed to deploy advanced AI in demanding environments. Our customers include some of the world’s largest enterprises, including organisations operating behind strict security, regulatory and technical constraints.
We’re also training Lumen Sovereign, the first frontier large language model trained in the UK, with the support of the UK Government.
We’re now looking for a Technical GTM Lead to become the technical centre of gravity for our go-to-market team.
You’ll sit at the intersection of customers, sales, product, engineering and machine learning. You’ll show prospective customers what Cosine can do, help existing customers get deployed, build the technical assets that make our products compelling, and ensure what we learn in the field directly improves what we build.
This is not a traditional solutions consultant role. It is highly hands-on. One day you may be running a technical evaluation with an enterprise engineering team; the next you may be debugging a deployment, building a demonstration environment, writing a technical blog or working with ML researchers to turn a new capability into something customers can understand and use.
___________________________________________________________________________
Lead technical demonstrations and evaluations for prospective enterprise customers.
Understand a customer’s development environment, architecture, security model and constraints, then tailor the conversation accordingly.
Explain Cosine’s products, models, integrations, deployment options and security considerations with accuracy and confidence.
Design and run technical evaluations, pilots and proofs of concept.
Work alongside the commercial team to help turn technical interest into customer momentum.
Create high-quality demo environments that show Cosine at its best.
Build reusable repositories, workflows and customer scenarios across our coding agent, desktop application and Sparklr model-training platform.
Develop technical materials that help the wider GTM team explain, demonstrate and position Cosine effectively.
Work with Product, Engineering and ML to turn new capabilities into compelling customer-facing demonstrations.
Create technical content such as blogs, product pages, webinars and enablement materials.
Own the technical side of customer onboarding, from initial architecture conversations through to a working deployment.
Help customers integrate Cosine with their existing repositories, development environments, infrastructure and enterprise systems.
Support deployments across cloud, VPC, on-premise and other controlled environments.
Troubleshoot issues directly and coordinate with Engineering when deeper product support is required.
Lead onboarding sessions and become a trusted technical counterpart for customer engineering, platform, security and AI teams.
Act as the primary technical bridge between GTM and Cosine’s Product, Engineering and ML teams.
Bring structured customer feedback into the product organisation, including recurring questions, blockers, feature requests and deployment issues.
Identify patterns across customer conversations and distinguish one-off requests from strategically important product gaps.
Help the GTM team understand new technical capabilities, product changes and their implications for customers.
Help Product and ML understand what enterprise customers actually need in order to adopt Cosine.
Become the first port of call for technical questions from the commercial team.
Build enough depth across Cosine’s products and underlying technology to explain not only what they do, but how and why they work.
Help the GTM team communicate technical capabilities accurately and avoid overpromising.
Train, document and support the wider commercial organisation.
Create a culture where technical rigour and commercial momentum reinforce each other.
___________________________________________________________________________
You may have come from software engineering, solutions engineering, forward-deployed engineering, developer tooling, technical product or a similar technical customer-facing role.
You should be comfortable:
Reading, writing and debugging code.
Working with Git, CI/CD, APIs, containers and cloud infrastructure.
Understanding enterprise deployment architectures, including cloud, VPC and on-premise environments.
Speaking credibly with software engineers, platform teams, security teams and technical executives.
Learning complex products quickly and explaining them clearly.
Debugging ambiguous customer problems and finding a practical path forward.
Moving between a customer meeting, a terminal and a conversation with an ML or Product team without losing context.
Making sound technical judgements without pretending to know what you do not know.
Experience with LLMs, coding agents, ML infrastructure or enterprise AI deployment would be valuable. But deep curiosity, technical ability and strong customer instincts matter more than having worked in exactly the same category before.
You do not need to be an ML researcher or the world’s best infrastructure engineer. You do need to be able to go deep when required, find the right answer quickly and communicate it in a way that earns trust.
___________________________________________________________________________
In your first three months, you will:
Become the person the GTM team relies on for difficult technical customer conversations.
Independently run excellent demonstrations across Cosine’s core products.
Build a useful library of repeatable demo environments, workflows and technical assets.
Reduce the friction and time involved in getting enterprise customers deployed.
Establish a strong feedback loop between customers, GTM, Product, Engineering and ML.
Give the commercial team confidence that Cosine can engage deeply with technically sophisticated customers.
Longer term, you will help define how Cosine is understood, evaluated and adopted by the world’s most demanding engineering organisations.
___________________________________________________________________________
Cosine is building technology that cannot be sold through a slide deck alone.
Our customers want to see the product working in their environments. They want to understand how it behaves across complex codebases, legacy systems, security boundaries and real development workflows. They want technically honest answers and a partner who can stay with the problem when deployment gets difficult.
You will be that person.
You’ll have unusual proximity to customers, product decisions and the underlying research. You’ll help shape the demonstrations, deployments and feedback loops that determine where Cosine goes next.
If you enjoy being close to the technology, close to customers and close to the teams building the future of AI, this is an opportunity to have a significant impact.
Come help make frontier AI useful.
___________________________________________________________________________
Why join Cosine
Opportunity to sell a genuinely differentiated product into mission-critical defence and national security environments
Meaningful early equity with real upside
Direct impact on product direction and go-to-market strategy
Small, elite team with high standards and strong technical depth
___________________________________________________________________________
We value diverse backgrounds, perspectives, and ways of thinking, and we’re committed to creating an inclusive and respectful workplace.
We encourage applications from anyone who meets the role requirements, even if you don’t meet every single qualification. If you need reasonable adjustments at any stage of the hiring process, we’re happy to discuss them.
___________________________________________________________________________
We’re an in-office team, five days a week, by design. We believe the work we’re doing benefits from being together, collaborating closely, and building shared context.
What you can expect:
Competitive salary, benchmarked to the market
Equity / share options, so you share in the upside you help create
30 days’ holiday + bank holidays
Work hard in the office, collaborate closely, and switch off properly
Dog-friendly office — bring your dog to work
Daily lunch provided
Monthly team breakfasts
Monthly socials
Pension
High-quality equipment to do your best work
We care about focus, sustainability, and doing great work — not performative overwork. We value people who show up, contribute thoughtfully, collaborate well with their colleagues, and then go home.
This role won’t suit everyone. But if you want structure, clarity, strong collaboration, and a team that takes both the work and work-life balance seriously, it’s a great place to be.
___________________________________________________________________________
To comply with UK GDPR and our internal data-protection and equal-opportunity obligations, we only accept candidate applications and agency submissions via our Applicant Tracking System (ATS). This ensures appropriate privacy notices, lawful processing, auditability, and consistent retention controls.
Any CVs or candidate details received outside the ATS (including via email, Slack, or direct message) will be treated as unsolicited, will not be considered as part of the recruitment process, and will not give rise to any fee or payment obligation.
","descriptionPlain":"Job title: Technical GTM Lead\n\nLocation: London; full in-office working as default\n\nStart date: ASAP\n\nReports to: CRO\n\nCompensation: Salary and Equity options available for discussion\n\nApplication deadline: 01/11/26 at 23:59 UK time\n\n___________________________________________________________________________\n\n\n\n\nHELP PUT FRONTIER AI TO WORK IN THE REAL WORLD\n\n\n\nCosine is a UK AI lab building models, applications and training infrastructure for mission-critical organisations.\n\nWe build coding agents that work across real software systems, specialised Lumen models, AI-native security products and the infrastructure needed to deploy advanced AI in demanding environments. Our customers include some of the world’s largest enterprises, including organisations operating behind strict security, regulatory and technical constraints.\n\nWe’re also training Lumen Sovereign, the first frontier large language model trained in the UK, with the support of the UK Government.\n\nWe’re now looking for a Technical GTM Lead to become the technical centre of gravity for our go-to-market team.\n\nYou’ll sit at the intersection of customers, sales, product, engineering and machine learning. You’ll show prospective customers what Cosine can do, help existing customers get deployed, build the technical assets that make our products compelling, and ensure what we learn in the field directly improves what we build.\n\nThis is not a traditional solutions consultant role. It is highly hands-on. One day you may be running a technical evaluation with an enterprise engineering team; the next you may be debugging a deployment, building a demonstration environment, writing a technical blog or working with ML researchers to turn a new capability into something customers can understand and use.\n\n___________________________________________________________________________\n\n\n\n\nWHAT YOU’LL DO\n\n\nMAKE COSINE REAL FOR CUSTOMERS\n\n - Lead technical demonstrations and evaluations for prospective enterprise customers.\n\n - Understand a customer’s development environment, architecture, security model and constraints, then tailor the conversation accordingly.\n\n - Explain Cosine’s products, models, integrations, deployment options and security considerations with accuracy and confidence.\n\n - Design and run technical evaluations, pilots and proofs of concept.\n\n - Work alongside the commercial team to help turn technical interest into customer momentum.\n\n\nBUILD THE TECHNICAL GTM ENGINE\n\n - Create high-quality demo environments that show Cosine at its best.\n\n - Build reusable repositories, workflows and customer scenarios across our coding agent, desktop application and Sparklr model-training platform.\n\n - Develop technical materials that help the wider GTM team explain, demonstrate and position Cosine effectively.\n\n - Work with Product, Engineering and ML to turn new capabilities into compelling customer-facing demonstrations.\n\n - Create technical content such as blogs, product pages, webinars and enablement materials.\n\n\nGET CUSTOMERS SUCCESSFULLY DEPLOYED\n\n - Own the technical side of customer onboarding, from initial architecture conversations through to a working deployment.\n\n - Help customers integrate Cosine with their existing repositories, development environments, infrastructure and enterprise systems.\n\n - Support deployments across cloud, VPC, on-premise and other controlled environments.\n\n - Troubleshoot issues directly and coordinate with Engineering when deeper product support is required.\n\n - Lead onboarding sessions and become a trusted technical counterpart for customer engineering, platform, security and AI teams.\n\n\nCONNECT CUSTOMERS, GTM AND THE PRODUCT ORGANISATION\n\n - Act as the primary technical bridge between GTM and Cosine’s Product, Engineering and ML teams.\n\n - Bring structured customer feedback into the product organisation, including recurring questions, blockers, feature requests and deployment issues.\n\n - Identify patterns across customer conversations and distinguish one-off requests from strategically important product gaps.\n\n - Help the GTM team understand new technical capabilities, product changes and their implications for customers.\n\n - Help Product and ML understand what enterprise customers actually need in order to adopt Cosine.\n\n\nRAISE THE TECHNICAL BAR\n\n - Become the first port of call for technical questions from the commercial team.\n\n - Build enough depth across Cosine’s products and underlying technology to explain not only what they do, but how and why they work.\n\n - Help the GTM team communicate technical capabilities accurately and avoid overpromising.\n\n - Train, document and support the wider commercial organisation.\n\n - Create a culture where technical rigour and commercial momentum reinforce each other.\n\n\n\n___________________________________________________________________________\n\n\n\n\nWHAT WE’RE LOOKING FOR\n\nYou may have come from software engineering, solutions engineering, forward-deployed engineering, developer tooling, technical product or a similar technical customer-facing role.\n\nYou should be comfortable:\n\n - Reading, writing and debugging code.\n\n - Working with Git, CI/CD, APIs, containers and cloud infrastructure.\n\n - Understanding enterprise deployment architectures, including cloud, VPC and on-premise environments.\n\n - Speaking credibly with software engineers, platform teams, security teams and technical executives.\n\n - Learning complex products quickly and explaining them clearly.\n\n - Debugging ambiguous customer problems and finding a practical path forward.\n\n - Moving between a customer meeting, a terminal and a conversation with an ML or Product team without losing context.\n\n - Making sound technical judgements without pretending to know what you do not know.\n\nExperience with LLMs, coding agents, ML infrastructure or enterprise AI deployment would be valuable. But deep curiosity, technical ability and strong customer instincts matter more than having worked in exactly the same category before.\n\nYou do not need to be an ML researcher or the world’s best infrastructure engineer. You do need to be able to go deep when required, find the right answer quickly and communicate it in a way that earns trust.\n\n\n\n___________________________________________________________________________\n\n\n\n\nWHAT SUCCESS LOOKS LIKE\n\nIn your first three months, you will:\n\n - Become the person the GTM team relies on for difficult technical customer conversations.\n\n - Independently run excellent demonstrations across Cosine’s core products.\n\n - Build a useful library of repeatable demo environments, workflows and technical assets.\n\n - Reduce the friction and time involved in getting enterprise customers deployed.\n\n - Establish a strong feedback loop between customers, GTM, Product, Engineering and ML.\n\n - Give the commercial team confidence that Cosine can engage deeply with technically sophisticated customers.\n\nLonger term, you will help define how Cosine is understood, evaluated and adopted by the world’s most demanding engineering organisations.\n\n___________________________________________________________________________\n\n\n\n\nWHY THIS ROLE MATTERS\n\nCosine is building technology that cannot be sold through a slide deck alone.\n\nOur customers want to see the product working in their environments. They want to understand how it behaves across complex codebases, legacy systems, security boundaries and real development workflows. They want technically honest answers and a partner who can stay with the problem when deployment gets difficult.\n\nYou will be that person.\n\nYou’ll have unusual proximity to customers, product decisions and the underlying research. You’ll help shape the demonstrations, deployments and feedback loops that determine where Cosine goes next.\n\nIf you enjoy being close to the technology, close to customers and close to the teams building the future of AI, this is an opportunity to have a significant impact.\n\nCome help make frontier AI useful.\n\n___________________________________________________________________________\n\nWhy join Cosine\n\n - Opportunity to sell a genuinely differentiated product into mission-critical defence and national security environments\n\n - Meaningful early equity with real upside\n\n - Direct impact on product direction and go-to-market strategy\n\n - Small, elite team with high standards and strong technical depth\n\n___________________________________________________________________________\n\n\n\nCOSINE IS AN EQUAL OPPORTUNITY EMPLOYER.\n\n\nWe value diverse backgrounds, perspectives, and ways of thinking, and we’re committed to creating an inclusive and respectful workplace.\n\nWe encourage applications from anyone who meets the role requirements, even if you don’t meet every single qualification. If you need reasonable adjustments at any stage of the hiring process, we’re happy to discuss them.\n\n___________________________________________________________________________\n\n\n\n\nCOMPENSATION, BENEFITS & WAYS OF WORKING\n\nWe’re an in-office team, five days a week, by design. We believe the work we’re doing benefits from being together, collaborating closely, and building shared context.\n\n\n\nWhat you can expect:\n\n - Competitive salary, benchmarked to the market\n\n - Equity / share options, so you share in the upside you help create\n\n - 30 days’ holiday + bank holidays\n\n - Work hard in the office, collaborate closely, and switch off properly\n\n - Dog-friendly office — bring your dog to work\n\n - Daily lunch provided\n\n - Monthly team breakfasts\n\n - Monthly socials\n\n - Pension\n\n - High-quality equipment to do your best work\n\nWe care about focus, sustainability, and doing great work — not performative overwork. We value people who show up, contribute thoughtfully, collaborate well with their colleagues, and then go home.\n\nThis role won’t suit everyone. But if you want structure, clarity, strong collaboration, and a team that takes both the work and work-life balance seriously, it’s a great place to be.\n\n___________________________________________________________________________\n\n\n\n\nAGENCY & DATA PROTECTION NOTICE\n\nTo comply with UK GDPR and our internal data-protection and equal-opportunity obligations, we only accept candidate applications and agency submissions via our Applicant Tracking System (ATS). This ensures appropriate privacy notices, lawful processing, auditability, and consistent retention controls.\n\nAny CVs or candidate details received outside the ATS (including via email, Slack, or direct message) will be treated as unsolicited, will not be considered as part of the recruitment process, and will not give rise to any fee or payment obligation."},{"id":"037ef467-a30c-4b14-86ac-f629d4d589d2","title":"Expression of Interest","department":"EOI","team":"EOI","employmentType":"FullTime","location":"London Office","secondaryLocations":[],"publishedAt":"2026-10-05T14:21:19.206+00:00","isListed":true,"isRemote":false,"workplaceType":"OnSite","address":{"postalAddress":{"addressRegion":"England","addressCountry":"United Kingdom","addressLocality":"London"}},"jobUrl":"https://jobs.ashbyhq.com/cosine/037ef467-a30c-4b14-86ac-f629d4d589d2","applyUrl":"https://jobs.ashbyhq.com/cosine/037ef467-a30c-4b14-86ac-f629d4d589d2/application","descriptionHtml":"London, UK
Cosine is a UK-based AI lab building autonomous software engineering systems for organisations where reliability, security and control matter most. We develop the models, agent tooling, infrastructure and products that enable AI to tackle complex software engineering work in real customer environments.
Our work brings together research, engineering and commercial teams to deploy advanced AI across enterprise, government, defence and other highly regulated sectors.
We welcome applications from talented people who want to help build Cosine, whether or not we have an advertised role that matches their experience.
For the right person, we can create an opportunity. This expression of interest is a direct route into our hiring process, allowing us to explore where your strengths could make the greatest contribution.
We’re particularly interested in ML engineers and researchers, alongside people with experience in software engineering, infrastructure, product, customer deployment and commercial growth.
ML engineering and research: Improve model capabilities through training, post-training, data curation, evaluation and efficient inference.
Software and infrastructure: Build the agent systems, developer tooling and deployment infrastructure behind reliable AI software engineering.
Product and customer deployment: Turn advanced capabilities into useful products and deploy them successfully in complex customer environments.
Commercial and partnerships: Build relationships, develop markets and help enterprise and public sector organisations adopt Cosine.
These areas give a sense of our work. We also welcome applications from people whose expertise could strengthen Cosine in other ways.
We value evidence of strong work: systems you’ve built, research you’ve delivered, products you’ve shipped or commercial outcomes you’ve achieved.
You’ll bring depth in your field, sound judgement and the ability to take ownership of difficult problems. You should enjoy working closely with people across disciplines and turning ideas into results.
You’ll have meaningful ownership of problems across models, agents, infrastructure, product and deployment, working closely with colleagues across research, engineering and commercial teams.
This is an opportunity to shape technology used in environments where quality and reliability have real consequences.
Submit your CV or LinkedIn profile through the application form below, along with a short explanation of what you’d like to contribute at Cosine. Include relevant projects, publications, a portfolio or examples of your work where useful.
Where we see a strong fit, we’ll arrange an initial conversation to discuss your experience and the role we could build around it.
You don’t need to wait for a matching vacancy. Apply below.
We value diverse backgrounds, perspectives, and ways of thinking, and we’re committed to creating an inclusive and respectful workplace.
We encourage applications from anyone who meets the role requirements, even if you don’t meet every single qualification. If you need reasonable adjustments at any stage of the hiring process, we’re happy to discuss them.
We’re an in-office team, five days a week, by design. We believe the work we’re doing benefits from being together, collaborating closely, and building shared context.
What you can expect:
Competitive salary, benchmarked to the market
Equity / share options, so you share in the upside you help create
30 days’ holiday + bank holidays
Work hard in the office, collaborate closely, and switch off properly
Dog-friendly office - bring your dog to work
Weekly team breakfast & lunch
Monthly socials
Pension
High-quality equipment to do your best work
We care about focus, sustainability, and doing great work - not performative overwork. We value people who show up, contribute thoughtfully, collaborate well with their colleagues, and then go home.
This role won’t suit everyone. But if you want structure, clarity, strong collaboration, and a team that takes both the work and work-life balance seriously, it’s a great place to be.
To comply with UK GDPR and our internal data-protection and equal-opportunity obligations, we only accept candidate applications and agency submissions via our Applicant Tracking System (ATS). This ensures appropriate privacy notices, lawful processing, auditability, and consistent retention controls.
Any CVs or candidate details received outside the ATS (including via email, Slack, or direct message) will be treated as unsolicited, will not be considered as part of the recruitment process, and will not give rise to any fee or payment obligation.
","descriptionPlain":"EXPRESSION OF INTEREST — JOIN COSINE\n\nLondon, UK\n\n\n\n\nABOUT COSINE\n\nCosine is a UK-based AI lab building autonomous software engineering systems for organisations where reliability, security and control matter most. We develop the models, agent tooling, infrastructure and products that enable AI to tackle complex software engineering work in real customer environments.\n\nOur work brings together research, engineering and commercial teams to deploy advanced AI across enterprise, government, defence and other highly regulated sectors.\n\n\n\n\nWE’RE ALWAYS HIRING EXCEPTIONAL PEOPLE\n\nWe welcome applications from talented people who want to help build Cosine, whether or not we have an advertised role that matches their experience.\n\nFor the right person, we can create an opportunity. This expression of interest is a direct route into our hiring process, allowing us to explore where your strengths could make the greatest contribution.\n\nWe’re particularly interested in ML engineers and researchers, alongside people with experience in software engineering, infrastructure, product, customer deployment and commercial growth.\n\n\n\n\nWHERE YOU COULD MAKE AN IMPACT\n\n - ML engineering and research: Improve model capabilities through training, post-training, data curation, evaluation and efficient inference.\n\n - Software and infrastructure: Build the agent systems, developer tooling and deployment infrastructure behind reliable AI software engineering.\n\n - Product and customer deployment: Turn advanced capabilities into useful products and deploy them successfully in complex customer environments.\n\n - Commercial and partnerships: Build relationships, develop markets and help enterprise and public sector organisations adopt Cosine.\n\nThese areas give a sense of our work. We also welcome applications from people whose expertise could strengthen Cosine in other ways.\n\n\n\n\nWHAT WE LOOK FOR\n\nWe value evidence of strong work: systems you’ve built, research you’ve delivered, products you’ve shipped or commercial outcomes you’ve achieved.\n\nYou’ll bring depth in your field, sound judgement and the ability to take ownership of difficult problems. You should enjoy working closely with people across disciplines and turning ideas into results.\n\n\n\n\nWHAT WE OFFER\n\nYou’ll have meaningful ownership of problems across models, agents, infrastructure, product and deployment, working closely with colleagues across research, engineering and commercial teams.\n\nThis is an opportunity to shape technology used in environments where quality and reliability have real consequences.\n\n\n\n\nAPPLY\n\nSubmit your CV or LinkedIn profile through the application form below, along with a short explanation of what you’d like to contribute at Cosine. Include relevant projects, publications, a portfolio or examples of your work where useful.\n\nWhere we see a strong fit, we’ll arrange an initial conversation to discuss your experience and the role we could build around it.\n\nYou don’t need to wait for a matching vacancy. Apply below.\n\n \n \n\n\nCOSINE IS AN EQUAL OPPORTUNITY EMPLOYER.\n\nWe value diverse backgrounds, perspectives, and ways of thinking, and we’re committed to creating an inclusive and respectful workplace.\n\nWe encourage applications from anyone who meets the role requirements, even if you don’t meet every single qualification. If you need reasonable adjustments at any stage of the hiring process, we’re happy to discuss them.\n\n \n \n\n\nCOMPENSATION, BENEFITS & WAYS OF WORKING\n\nWe’re an in-office team, five days a week, by design. We believe the work we’re doing benefits from being together, collaborating closely, and building shared context.\n\nWhat you can expect:\n\n - Competitive salary, benchmarked to the market\n\n - Equity / share options, so you share in the upside you help create\n\n - 30 days’ holiday + bank holidays\n\n - Work hard in the office, collaborate closely, and switch off properly\n\n - Dog-friendly office - bring your dog to work\n\n - Weekly team breakfast & lunch\n\n - Monthly socials\n\n - Pension\n\n - High-quality equipment to do your best work\n\nWe care about focus, sustainability, and doing great work - not performative overwork. We value people who show up, contribute thoughtfully, collaborate well with their colleagues, and then go home.\n\nThis role won’t suit everyone. But if you want structure, clarity, strong collaboration, and a team that takes both the work and work-life balance seriously, it’s a great place to be.\n\n \n \n\n\nAGENCY & DATA PROTECTION NOTICE\n\nTo comply with UK GDPR and our internal data-protection and equal-opportunity obligations, we only accept candidate applications and agency submissions via our Applicant Tracking System (ATS). This ensures appropriate privacy notices, lawful processing, auditability, and consistent retention controls.\n\nAny CVs or candidate details received outside the ATS (including via email, Slack, or direct message) will be treated as unsolicited, will not be considered as part of the recruitment process, and will not give rise to any fee or payment obligation."}],"apiVersion":"1"}