Build the future of sovereign AI
Join the team that is leading the way in building technology that helps teams make better decisions without compromising on privacy or control.
Why work at Cosine
Build the future of AI
Work on autonomous software engineering systems that go beyond chat and autocomplete. Help build AI agents that can plan, reason, write, test, and ship code inside real development workflows.
Own the full stack
Shape the models, agent infrastructure, evaluation harnesses, product surfaces, and deployment systems that make Cosine work. We build deeply in-house, so your work directly influences what the product can become.
Ship technology that matters
Build AI that serious teams can rely on in secure, high-trust environments. Your work will help defense, finance, government, healthcare, and enterprise teams use AI where reliability, privacy, and control matter most.
Benefits and ways of working
We want Cosine to be a place where ambitious people can do the best work of their careers without relying on excessive hours or performative overwork. Our compensation, benefits, and working practices are designed to reward contribution fairly, support wellbeing, and align the team with Cosine’s long-term success.
Compensation and ownership
We offer competitive salaries, paid monthly. Eligible employees may also receive share options, giving the team a direct stake in the long-term value they help create.
Pension
Cosine provides a workplace pension through NEST, in line with UK pension requirements with a salary sacrifice pension arrangement available.
Focused working hours
Our standard working hours are 9:00am to 5:00pm, Monday to Friday, unless otherwise agreed. We do not expect regular late working, weekend work, or constant availability.
In-office by design
Cosine is primarily an in-office company because the work benefits from close collaboration, fast feedback, and shared context. Office attendance is about focus and momentum, not longer working hours.
Everyday benefits
Cosine currently offers benefits that may include a Cycle to Work scheme, weekly free meals in the office, unlimited snacks and drinks, and a pet-friendly office.
Team connection
We make space for people to connect through monthly team breakfasts, monthly socials, and quarterly company events or offsites.
Work from abroad
Employees may request to work from another location for up to one month per calendar year, subject to manager approval. This is designed to support flexibility and wellbeing while keeping Cosine’s in-office working model intact.
Inclusion and working styles
Cosine is committed to creating an inclusive and psychologically safe workplace. We respect different working styles, communication preferences, and ways of thinking, and we want people to be able to do excellent work without masking who they are.
How we work at Cosine
We’re building systems that engineers can trust in real production environments. That takes high standards, direct communication, deep ownership, and a team that values practical progress over theatre. These are the principles that shape how we work, hire, and make decisions.
Do the hard thing
The future of AI engineering will not be built by taking the easy path. We choose the work that matters, stay with difficult problems, and take responsibility for building systems that can stand up to real-world use.
Be customer-obsessed
Our customers work in environments where reliability, privacy, and control matter. We take their problems seriously, understand their world deeply, and build technology that earns trust through performance.
Stay curious
Cosine sits at the intersection of models, agents, infrastructure, product, and enterprise deployment. We stay curious across all of it, because the best ideas often come from people who understand more than their own lane.
Own it
High-agency people build Cosine. We take responsibility for outcomes, communicate clearly, and turn ambiguity into forward motion.
Voice it clearly
We get to better answers through honest, respectful debate. We raise ideas, concerns, and disagreements early, then commit to the path once a decision is made.
Open roles
ML Systems Engineer, Model Training and Infrastructure
Build and run the training systems behind Cosine’s Lumen software engineering models, including synthetic data pipelines, supervised fine-tuning, RL environments, reward functions, and evaluation suites. Work across Python, Go, PyTorch, containers, cloud infrastructure, and real-world code tasks to make Cosine’s models better at writing maintainable, production-quality software.
Full Stack Product Engineer
Build the user-facing product surfaces that bring Cosine’s models into developer workflows, including CLI, web, app, and platform experiences. Work across product, design, research, infrastructure, and engineering to turn new model capabilities into fast, reliable, intuitive tools for developers.
Strategy & Operations
Help Cosine turn enterprise and sovereign AI opportunities into repeatable systems for partnerships, procurement, onboarding, reporting, compliance, and market exploration. Work across commercial, product, finance, and leadership teams to bring structure to fast-moving projects and keep strategic customer and partner work moving.