Principal Full Stack JavaScript Engineer

Type: Full-time, Permanent Location: UK-based (flexible home, office, or hybrid working) Office locations: Newcastle and Leeds Hub locations: Edinburgh, Manchester, London 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 hedgehog lab is a digital product consultancy with 20 years of experience. Based in Northern England, we help global brands craft better digital experiences through technical excellence and human-first collaboration. hedgehog lab benefits * 28 days of annual leave plus bank holidays * 5 Impact Days per year to spend on L&D, volunteering or innovation * Flexible working environment * Enhanced parental policy * Annual wellbeing budget + two days of wellbeing * Mental health support * Company-supplied Apple Mac 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.