Full stack developer to fix webapp

Looking for an experienced full-stack developer to work on a web platform focused on security hardening, performance optimisation, and SEO improvements. The project involves backend (Node.js / Express / Prisma / PostgreSQL) and frontend (Next.js 15 / React 19) work. A detailed technical audit has already been completed — you will receive a prioritised list of issues with file references, root cause analysis, and recommended fixes. No discovery work needed. What the work covers: • Security: fixing authentication gaps, hardening API routes, correcting middleware configuration • Performance: eliminating N+1 database queries, optimising indexes, improving caching • SEO: server-side rendering improvements, structured data, metadata • Code quality: removing dead code, resolving dependency conflicts, minor refactors Required skills: • Strong Node.js / Express backend experience • Next.js App Router (not Pages Router) • Prisma ORM and PostgreSQL • Solid understanding of web security fundamentals (auth, CORS, JWT, rate limiting) • Ability to work from a written brief without hand-holding • Clean, testable code — no cowboy fixes Nice to have: • Experience with Stripe webhooks • Pusher / real-time features • Cloudinary uploads • VPS deployment This is a fixed-scope engagement. Estimated effort is 50–100 hours depending on scope agreed. Looking for someone detail-oriented who reads the brief before asking questions.