Junior Full stack Engineer in Kensington

Junior Full Stack Engineer – Health-Tech Startup (YC-Backed) London | ON SITE | Permanent We're hiring on behalf of a fast-moving, YC-backed health-tech startup building a knowledge graph connecting over 9 million US healthcare professionals, turning fragmented data into real-time signals for pharma teams. This is a role for someone early in their career who's already built something real, whether that's a side project, an open-source tool, a hackathon win, or your own product, and wants to keep building at pace with a small team that gives you real ownership from day one. What you'll do * Own real pieces of data infrastructure and product from an early stage * Work through messy, ambiguous problems: a confusing data source, an unclear requirement, something that just needs solving. You'll work out what "good" looks like and build it * Get hands-on with Python, SQL, MongoDB, TypeScript, React, and LLMs in production pipelines What we're looking for * Evidence you can learn and build fast: a strong personal project, competitive performance, research, or work well beyond your level. We care about the evidence, not where it came from * You've taken something from an idea to something real, used, depended on, or running in production. Not just coursework * Genuine appetite for ambiguity, messy data, and early-stage pace * Comfortable in a small, fast-moving team with real responsibility from the start Nice to Have * Background in bio-pharma, healthcare data, or life sciences * Prior experience as a founding engineer or early technical hire at a startup