Full Stack Engineer

London (Hybrid) · £80,000–£100,000 Everyone in AI is obsessed with the models. Almost nobody is thinking about what those models are actually trained on. We're hiring on behalf of a London-based, Techstars-backed generative AI company building the layer everyone else depends on and nobody else is building properly: rights-cleared, human-generated training data for multimodal AI — video, speech, and music. The "data backbone for Gen AI." The pace is the headline: Annotator workforce scaled from 5 to 3,000 in nine weeks (600×) $5M seed round actively in progress, on top of $10M already raised $7m ARR already achieved with over $100M qualified pipeline built in the last three months This is a five-person, backend-heavy engineering team at the point where enterprise delivery is accelerating faster than they can build. They need a fullstack engineer who can lead workstreams, bring real frontend depth, and own problems end-to-end. What you'll do Lead workstreams within the sprint cycle and beyond — taking pressure off the senior team Take vague briefs, scope them yourself, and ask the questions that surface the real requirements Own development end-to-end: build, test, monitor, debug, and tune performance Generate ideas at the solution and initiative level, not just clear tickets Help scale engineering practices as the team grows What we're looking for 3–5 years as a fullstack engineer, in a startup or scale-up Strong Python backend — Django, or a framework that transfers directly Solid React frontend — the team is backend-heavy, so frontend depth is genuinely valuable A demonstrable build track record — GitHub or a portfolio of things you've actually shipped Nice to have Cloud / DevOps depth on any major cloud (AWS today, GCP migration imminent; Kubernetes in production) Terraform, cost management, incident response across the stack Training-data or data-labelling experience — heavily weighted Data engineering and data structuring (more important than the music/media domain itself) Why this seat, now You'd be joining a five-person team during hyper-growth, leading workstreams from day one, with a clear path to senior — and, for commercially-minded engineers, a route into product. Production at real scale, and genuinely novel scaling problems in multimedia and training data. No bureaucracy. Ideas heard at the level they're made. The stack matters less than you'd think. What matters is your appetite for growth — and the pace here is genuinely rare. The essentials Location: London, hybrid and flexible by definition. Rest of UK fine; UK/EU time zone required. Salary: £80,000–£100,000 Stack: Python · Django · React · Redis · PostgreSQL · AWS→GCP · Kubernetes Process: intro call → technical & cultural round → in-person onsite with the team Interested? Apply or message us — happy to walk you through the company properly.