Senior Full Stack Developer (MERN) — Platform Maintenance & On-Call Support

About the Role We're looking for a senior full stack developer to take over ongoing maintenance and support for a live F&B ordering platform (multi-restaurant marketplace: restaurant owners, staff, and end customers) launching in the UK. The platform is already built — this is a maintenance and incident-response role, not greenfield development, with a steady stream of small enhancement requests on top. You'll be the primary technical owner responsible for keeping the platform stable, secure, and fast, plus handling minor product change requests as they come up. Tech Stack MongoDB — database Express / Node.js — backend, API React — frontend Cloud hosting (details shared with shortlisted candidates) Payment gateway integration (details shared with shortlisted candidates) Scope of Work Standing responsibilities: Own uptime/error monitoring (Sentry, UptimeRobot or similar) and act on alerts Weekly verification of automated database backups Monthly security patching and dependency updates Monthly performance review (API response times, query efficiency, load handling during peak ordering hours) Manage releases/deployments with rollback capability Reactive: Triage and fix reported bugs across frontend, backend, and database layers Respond to critical incidents (platform down, orders failing) within agreed SLA Minor enhancements: UI/copy changes, form/validation tweaks, small flow adjustments, notification/email template edits Required Experience 4+ years professional experience with the MERN stack Strong REST API and authentication flow experience Experience with payment integrations (Stripe or similar) Comfortable owning deployments and basic DevOps (CI/CD, environment management) Prior experience in an on-call/maintenance capacity, not just feature-building English fluency (written and spoken) for async + live sync calls Coverage & SLA Expectations UK-market platform — peak traffic is UK evening dinner service (approx. 19:00–23:00 UK time). Candidate must be able to realistically cover this window for critical alerts, not just business hours. Priority Example Response Target P1 — Critical Platform down, orders not processing 30–60 min P2 — High Core feature broken (menu, cart, checkout) Same business day P3/P4 — Minor UI bugs, cosmetic, copy changes Within the week, batched Engagement Structure ~20–25 hours/month of scoped work, plus on-call availability for P1/P2 incidents Weekly async check-in; monthly call Hours tracked against a shared log Handover period expected (codebase, architecture docs, access) before independent on-call begins What We Provide Full codebase access and existing architecture/handover documentation Existing test case library Direct access to founders for scoping decisions