---
title: 'Expression of Interest at Cosine'
canonical: 'https://feeny.ai/job/expression-of-interest-cosine-london-e81t81xzwf0e'
type: 'job'
last_seen: '2026-10-19'
---

# Expression of Interest at Cosine

- **Company:** Cosine
- **Location:** London, United Kingdom
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-10-05
- **Last confirmed live:** 2026-10-19
- **Apply:** https://jobs.ashbyhq.com/cosine/037ef467-a30c-4b14-86ac-f629d4d589d2

## Job description

Expression of Interest — Join Cosine London, UK

## About Cosine

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’re always hiring exceptional people 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.

Where you could make an impact

- 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.

## What we look for

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.

## What we offer

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.

Apply 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.

Cosine is an equal opportunity employer. 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.

## Compensation, Benefits & Ways of Working

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.

Agency & Data Protection Notice 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.

## About Cosine

## Company Overview
- **One-liner**: Cosine is a sovereign AI frontier lab and developer of Lumen, a specialist coding model and fully agentic software engineering system that outperforms generalist models on real-world code tasks.
- **Entity Type**: Private (Venture-backed)
- **Headquarters**: London, United Kingdom
- **Founded**: 2022
- **Founders**: Yang Li, Alistair Pullen, Sam Stenner

## Core Business
- **Primary Industry**: Artificial Intelligence, Software Development
- **Target Customers**: Enterprise, Defense, Finance, Government, Healthcare, and other high-security, high-trust environments (B2B)
- **Mission**: Build sovereign AI engineering systems that serious teams can rely on in secure environments where reliability, privacy, and control matter most.

## Products & Services
- **Lumen (Model Family)**: A specialist family of AI models trained exclusively on production-quality code. Outperforms generalist models (OpenAI, Anthropic, DeepSeek) on code benchmarks. Includes variants:
    - **Scout** (8B parameters): Fast, on-device, for in-repo context.
    - **Outpost**: Post-trained from Kimi K2.6, optimized for enterprise and niche languages (COBOL, Fortran, Verilog, Rust, complex SQL).
    - **Frontier**: Highest-performing model (coming soon), achieving 59.3% on internal Niche-Bench vs. GPT-5.4 (47.4%).
- **Cosine Agent**: A fully agentic SWE that allows users to work on tickets asynchronously. Operates within a terminal-native interface, with multi-agent orchestration, MCP tool access, and a local-to-remote execution model.
- **Cosine Cloud**: Fully managed public cloud offering for teams.
- **Enterprise Deployment**: Managed single-tenant cloud and fully air-gapped on-premise deployments for maximum security.

## Market Standing
- **Valuation**: Not disclosed
- **Key Metric**: Annual Revenue of **$1.0M** (as of latest data); Total Funding of **$3.0M**.
- **Funding History**:
    - Pre-Seed (Nov 2022): $500K, led by Y Combinator (W23 batch).
    - Seed (Aug 2024): $2.5M, led by UpHonest Capital and Soma Capital (6 investors).
    - Grant (Apr 2026): 1 investor.
- **Notable Investors/Partners**: Y Combinator, UpHonest Capital, Soma Capital; Member of UK government’s £500M **Sovereign AI programme**; granted access to the **Isambard-AI** supercomputer.
- **Growth Signals**: Headcount has grown **60.9% YoY** (to ~23 employees); has assembled a UK Sovereign AI coalition of defense, infrastructure, financial, and healthcare leaders. Models have topped public benchmarks for two consecutive years.

## Competitive Advantages
- **Specialist-Over-Generalist Moat**: Lumen is a model trained exclusively on production code, not general text; this leads to significantly better results on code benchmarks (e.g., 59.3% on Niche-Bench vs. GPT-5.4’s 47.4%).
- **Sovereign AI**: First company to train, own, and deploy a fully sovereign AI model entirely on UK soil. This is a critical differentiator for defense, national security, and critical infrastructure where foreign AI is legally off the table.
- **Full-Stack In-House Build**: Owns the entire stack (models, agent infrastructure, evaluation, product surfaces, deployment) allowing deep integration and rapid iteration.
- **Real-World Deployment**: Deployed in air-gapped, on-premise environments for security-conscious customers who cannot use cloud-based AI.

## Strategic Focus
- **Sovereign AI Leadership**: Deepening its role as Britain’s national AI champion, working with the UK government on the £500M Sovereign AI programme.
- **Enterprise & Government Sales**: Expanding into defense, finance, infrastructure, and healthcare with secure, private deployments.
- **Pushing Agentic Boundaries**: Moving beyond chat and autocomplete to build AI agents that plan, reason, write, test, and ship code inside real development workflows.
- **Technical Scaling**: Building larger, more capable Frontier models and improving the training infrastructure (synthetic data, RL, reward functions).

## Why Work Here
- **Pioneering Work**: Build the future of autonomous software engineering at a company that leads the field in code-focused AI.
- **High Ownership**: Engineers own the full stack; work directly influences what the product becomes.
- **Culture**: Emphasizes direct communication, deep ownership, customer obsession, and “doing the hard thing.” Avoids performative overwork (standard 9-5, no regular late work or weekends).
- **In-Office by Design**: Primarily in-office (London) for close collaboration and fast feedback.
- **Benefits**: Competitive salaries, share options, pension (NEST), cycle-to-work scheme, weekly free meals, unlimited snacks/drinks, pet-friendly office, monthly team breakfasts/socials, quarterly offsites. Can request to work abroad up to one month per year.
- **Team**: Small (~23 people), high-agency, with deep technical talent.
- **Open Roles** (as of latest): ML Systems Engineer (Model Training & Infra), Full Stack Product Engineer, Strategy & Operations.

## Sources
1. [cosine.sh](https://cosine.sh/)
2. [cosine.sh/careers](https://cosine.sh/careers)
3. [Y Combinator](https://www.ycombinator.com/companies/cosine)
4. [LinkedIn](https://uk.linkedin.com/company/cosine-ai)
5. [Ashby Jobs](https://jobs.ashbyhq.com/cosine)

## Other roles at Cosine

- [Applied ML Technical Lead, Defence](https://feeny.ai/job/applied-ml-technical-lead-defence-cosine-london-5c1qhcd3naj2) — London, United Kingdom
- [Machine Learning Engineer – Lumen Enterprise Models (SWE-focused LLMs)](https://feeny.ai/job/machine-learning-engineer-lumen-enterprise-models-swe-focused-llms-cosine-london-7hvn96cw2cfb) — London, United Kingdom
- [Defence Account Director](https://feeny.ai/job/defence-account-director-cosine-london-6tdgd3k097py) — London, United Kingdom
- [Founding Healthcare Lead](https://feeny.ai/job/founding-healthcare-lead-cosine-london-q1j3kqfat5s0) — London, United Kingdom
- [Strategic Partnerships Manager](https://feeny.ai/job/strategic-partnerships-manager-cosine-london-43kyjed5b9qe) — London, United Kingdom
- [ML Systems Engineer - Model Training and Infrastructure (SWE-focused LLMs)](https://feeny.ai/job/ml-systems-engineer-model-training-and-infrastructure-swe-focused-llms-cosine-2zc7z5va8axx) — London, United Kingdom
- [Technical GTM Lead](https://feeny.ai/job/technical-gtm-lead-cosine-london-jqsgvabjdw8w) — London, United Kingdom
- [Expression of Interest](https://feeny.ai/job/expression-of-interest-sundrive-sydney-7zx4qxx0s8bn) — Sydney, Australia
- [Expression of Interest](https://feeny.ai/job/expression-of-interest-sigma-prime-global-1nh3v9gsjn82) — Global
- [Expression of Interest](https://feeny.ai/job/expression-of-interest-breadcrumb-melbourne-4z1c8nxhsy9j) — Melbourne, Australia