Principal Full Stack JavaScript Engineer - Contract

London 5 days agoContractor External
Negotiable
Type: Full-time, Contract (outside IR35) Location: UK-based (flexible home, office, or hybrid working) Office locations: Newcastle and Leeds Hub locations: Edinburgh, Manchester, London Start date: Monday 2nd Feb (must be immediately available) We’re growing our Engineering team to strengthen our ability to deliver world-class digital products for our clients. As a Principal Full Stack JavaScript Engineer, you’ll join a small, highly technical group tackling a complex transformation: breaking down a monolithic JavaScript platform into clearer, modern components. This is an individual contributor role for someone who thrives on problem-solving, can ramp up quickly, and can collaborate confidently with other very strong engineers. You’ll be hands-on from day one, helping modernise architecture, improve maintainability, and set the foundations for future technology decisions, all while staying pragmatic and delivery-focused. What you'll do • Lead (hands-on) full-stack engineering across a JavaScript platform, with a strong focus on architecture and problem-solving. • Break down an existing monolithic system into well-structured components and services. • Work closely with senior client engineers, ask the right questions, and influence technical direction through evidence and collaboration. • Support a move from Vercel-hosted deployment towards a Google Cloud future, improving deployment and operational readiness. • Contribute to authentication modernisation by integrating an identity platform rather than maintaining bespoke authentication. • Deliver value quickly by quickly understanding the domain, codebase, and priorities. Who is hedgehog lab We're an outcome-driven product consultancy where product, design, and research sit side by side. You'll join a team that values curiosity, collaboration and impact, building products that truly matter. What we’re looking for • Deep expertise in JavaScript (TypeScript a plus). • Strong full-stack experience, including Node.js and API architecture. • A pragmatic mindset: you care about quality, but you also deliver outcomes and keep momentum. • Confident communicator who can hold their own in technical discussions with senior engineers. • Comfortable working in small, flat teams with little hierarchy and lots of collaboration. Nice to have • Experience with Google Cloud (especially identity or auth-related services). • Experience with Vercel or modern web deployment platforms. • Interest or experience in open source communities or open source strategy. • Exposure to geospatial/GIS/mapping products or highly interactive map UIs. Ready to apply? Submit your application below. Please note that we’re unable to offer visa sponsorship for this role.