Founding Engineer

TL;DR Founding Engineer London (King's Cross) On-site, 5 days a week Up to £170k plus significant equity Visa sponsorship available The Company: They build agent-native risk infrastructure. Their agents run continuously on proprietary data, reassessing as things change instead of checking in at fixed intervals, and they sit on one platform that acts as the system of action, not just another workflow tool. They hit a $1M ARR run rate about nine months after going to market, with a three-person team. They've just closed a well-backed seed round, UK and US institutional investors, with angels who've built at Meta, Isomorphic Labs, Palantir, and SpaceX. Series A is planned for H2 2027. The role: You'll help decide what's worth building, design it, and ship it end to end: interface, API, agent-powered features, all of it. You own outcomes, not tickets. They're small and don't split into separate frontend, backend, or infra teams, so this role touches everything. Claude Code and modern AI tooling are part of the daily workflow, not a bolt-on. What you'll do: Decide, build, and ship customer-facing features across the full stack: React UI, API, data model, agent-powered functionality.Own outcomes end to end rather than working through a backlog someone else wrote.Work directly with the founders and a small senior team. No layers in between.Use Claude Code and similar tooling as a core part of how you build. What they're looking for: 6+ years shipping production software across the stack, ideally in TypeScript (or something close, with real appetite to switch), on a small fast-moving team.A track record of deciding on, building, and shipping things customers actually use.Real product instinct. You'd rather ship something useful than something impressive.Front-to-back range: comfortable in React, comfortable in the API and data layer.High agency. You see the gap and close it, nobody has to ask.Startup experience and a genuine appetite for early-stage risk. This is a seed company, there's a lot to build and real uncertainty alongside the upside. Nice to have: Real design chops, experience folding LLM features into a product, B2B SaaS/GRC/security exposure, early-stage or founding-team background. They're especially keen on strong engineers from big tech who've also done a stint at a startup, but pedigree isn't a gate here. Self-taught and non-traditional backgrounds are welcome if you can show the agency and instinct. Logistics: Location: King's Cross, London. In-office 5 days a week is where we're at right now. Occasional WFH is fine for the right person, but this isn't a 2-3 day remote setup.Comp: up to £170k base plus significant EMI-eligible equity (the most tax-efficient UK scheme). There's a cash-leaning option and an equity-leaning one, depending on what you'd rather optimise for.Visa sponsorship: available for the right person, Skilled Worker or Global Talent.Process: behavioural screen, technical screen, then a paid on-site work trial before an offer. Usually under two weeks start to finish. If full-stack product isn't quite your shape, we're also hiring for: Founding Engineer, Agent Systems. Owns the agent platform: orchestration, evals, reliability, the stuff that turns model calls into features customers actually trust. Good fit if you've shipped production LLM or agent work and want to own AI quality end to end. Founding Engineer, Infrastructure & Platform. Owns the platform layer: multi-tenant backend services, Azure and Terraform foundations, security posture, compliance (SOC 2, ISO 27001). Good fit for 6+ years of deep infra experience. Same location, comp, and process. If you're not sure which one fits, tell us what you've built and we'll work it out together.