Do you want to join a scale-up fitness startup in full expansion mode? If so, you have stopped at the right place! We are looking for someone to join our client's in-house product team. Contract : freelance or permanent | Industry : Proptech/Fitness | Start : June 1st A London-based fitness scale-up whose platform manages dynamic bookings, PT matching, and studio analytics. Stack: React Native (Expo), Next.js, Supabase, Vercel/AWS, Stripe, GitHub Actions, Hex, Figma — with a growing IoT footprint across studios. The Role You'll be the second Full Stack engineer, reporting to the Tech Lead. Wide surface area, real ownership, and a direct line into product and commercial decisions. This is a 2026 Product Engineer role. You own the loop from Figma to production, including QA, releases, observability, and postmortems. AI tooling (Claude Code is part of the daily workflow) makes that surface area manageable. It doesn't lower the bar. For the right person, this is a genuine career accelerator — with a clear path to a Lead Engineer position as the team grows. What You'll Do Build across Next.js, Supabase, and React Native — features end-to-end from design to production Own mobile releases on App Store and Google Play (versioning, staged rollouts, rejection handling) Integrate and maintain Stripe: subscriptions, webhooks, reconciliation, edge cases Contribute to the analytics pipeline and Hex dashboards Own and improve CI/CD pipelines (GitHub Actions, static analysis, type checking, tests) Level up testing discipline: unit, integration, E2E (Playwright / Maestro) Use AI tooling as a force multiplier — build workflows, review output critically, raise the team's bar Write documentation that survives you: ADRs, runbooks, READMEs Take your turn on production issues and write honest postmortems What We're Looking For Core experience 5 years full-stack with production Node.js, Next.js, and React Native Supabase fluency, or deep enough Postgres (RLS, functions, realtime) to get there fast Shipped mobile apps to both stores — including review rejections and staged rollouts Real production Stripe: webhooks, idempotency, retries, reconciliation Vercel experience: preview deployments, edge functions, environment management Figma-to-code fluency with design system judgment Designed and owned CI/CD pipelines with quality gates (SonarQube, CodeQL, or similar) How you work Daily Claude Code usage — you can talk about what works, what doesn't, and where it breaks. Clear view of what good code looks like; hold the line under pressure Test your own work before handoff; own it when something slips through Write things down so the next person doesn't have to ask Nice to have IoT integrations (smart locks) · Fitness, hospitality, or bookings background · Webflow Terms & Benefits Salary: £40,000–£50,000 depending on experience, plus equity Remote anywhere in the UK or EU, UK business hours (9 am–6 pm GMT/BST) 28 days holiday, including bank holidays, increasing with service Free Solo60 sessions and full studio access Equipment of your choice · Pension Interview Process Three stages, target two weeks, no LeetCode. Stage 1 — Technical Deep Dive (90 min) with Tech Lead Steve: your experience, how you approach product requirements, and debugging production issues. Stage 2 — Product & Collaboration (45 min) with CPO Yoann: working with product teams, building against a roadmap, using data to inform decisions. Stage 3 — Founder Conversation (30 min) with CEO Ben: broader business discussion. Offer shortly after if all goes well. Apply with a motivation note. Ps: NO RECRUITER.