Senior Full-Stack Developer (React / Supabase / TypeScript)

About the Client
Our client is a UK-based company operating a live B2B SaaS multi-module platform which is already serving paying users. They are currently undergoing a structured transition from a rapidly AI-prototyped codebase (using Lovable.ai) to a production-grade solution — built for long-term scalability and maintainability.

Job Description
We are looking for a Senior React / Supabase / TypeScript Developer who will take ownership of refactoring and hardening an existing SaaS platform. The core product logic, UI, and data layer are functional — this is not a rebuild. The goal is to elevate code quality, architecture, and operational reliability to production standards.

Stack

• Frontend: React 18, TypeScript, Vite, Tailwind CSS, shadcn/ui, React Router.
• Backend: Supabase (PostgreSQL, RLS, Deno Edge Functions, Auth, Realtime).
• Payments: Stripe (subscriptions, webhooks, metered billing).
• Auth: Google OAuth via Supabase Auth.
• Deployment: Currently Lovable Cloud (migration to Vercel or similar is in scope).
• AI Layer: External LLM API calls orchestrated through Edge Functions (you won’t need to write prompts, but you will need to understand and refactor the function architecture around them).

Scope of Work
The engagement is structured across three sequential phases.
Phase 1 — Audit & Architecture Proposal. Full codebase audit with a written proposal and prioritised recommendations. Sign-off from the client required before proceeding to Phase 2.
Phase 2 — Refactor & Harden. Systematic refactoring of the frontend architecture, Edge Functions, RLS policies, Stripe integration, and performance optimisation.
Phase 3 — Testing & CI/CD. Test coverage for critical paths, CI/CD pipeline setup, staging and production environments, and technical documentation for team onboarding.

Engagement & Payment
This is hourly, project-based engagement. Phase 1 is scoped as a standalone paid deliverable — upon successful completion, we move forward with Phases 2 and 3.

Requirements

• Proven experience refactoring an AI-generated or rapidly prototyped React + Supabase codebase to production grade — mandatory.
• Strong expertise in React 18, TypeScript, and component architecture patterns.
• Deep hands-on knowledge of Supabase: RLS policies, Deno Edge Functions, Auth, and Realtime.
• Experience with Stripe billing integrations (subscriptions, webhooks, lifecycle events).
• Familiarity with Vite, shadcn/ui, Tailwind CSS, and React Router
• Experience setting up CI/CD with GitHub Actions and modern deployment platforms (Vercel or similar).
• English — B2+ (working proficiency required for client communication).

Send us your CV — we'll be happy to work together!