APPLY TO SPEEDRUN
← All roles
Stealth · Hiring

Founding Engineer

London, UKOn SiteFull Time

Join an elite team to define how work happens in the agentic era.

We're rethinking how organizations share context and coordinate, from first principles, with fundamentally new infrastructure for safe, governable, and privacy-respecting agent-to-agent collaboration. We're live in dozens of companies, including name brands, with a waitlist five times that size. We've raised nearly $5M in unannounced funding and are now heads-down building as we assemble a world-class team.

Our founders include a CEO who got her PhD at 21 from Oxford, building agent-based models of coordination; a CTO who spent decades building agents and semantic tech as a leading computer scientist at MIT and Oxford; and a CCO who previously ran viral marketing campaigns and worked on commercial strategy for a Sequoia-backed startup.

We're looking for excellent members of technical staff who want a fast-paced, high-ownership 0-to-1 environment that combines product craft, applied research, and deep systems expertise.

The roles

We're hiring for multiple roles across:

Backend (platform and infrastructure). Our first infrastructure hires. Cloud setup, Postgres end to end, deployment, observability, on-call, security, and the cost of running inference at scale. Some of what exists was built fast and you'll want to redo parts of it. Your decisions become how we do infrastructure.

Full-stack (AI and product engineering). The web app in React, the LLM pipelines behind it, the MCP server agents talk to, and the integrations that feed the world model. You'd work with our front-end engineer and set how product engineering runs here.

You

TypeScript experience. Our stack is TypeScript end to end, Deno on the backend.

You use coding agents on your own work and have your own approach to setting them up for success.

For the backend role: serious Postgres experience under load, cloud fluency that comes from operating production systems, and an ops mindset. You've done on-call and you think about threat models without being asked.

For the full-stack role: creative product and design mindset, LLM pipelines in production (multi-step, evals, structured output, not one API call), and experience keeping third-party integrations alive at scale. Taste, in code and in prose.

Opinionated but open-minded, whether the argument is about product experience or core architecture. We look for evidence of craft.

Mostly: you see what's broken and fix it before anyone asks.

Successful candidates have usually already shown excellence somewhere, whether in their education, work, technical projects, or how they approach applying. We reciprocate by keeping the team small and in person, with a shared high bar, so you'd learn from peers you can trust and respect.

London or SF, in the office every day. We can sponsor visas. Top-of-market cash and founding equity.

Apply to this role

This company is in stealth. Apply right here, no redirect - they will see your application directly.

Name *
Email *
Resume *
LinkedIn Profile *
Location *
Additional links - GitHub, portfolio, or personal site *
Work authorization or relocation - anything we should know for this role's location?
Education History
What you built and are most proud of

By applying, you also join the speedrun talent network: if Stealth doesn't move forward, other speedrun portfolio companies can reach out about their roles.