Platform Engineer + App Rebuild Partner for low-code to full-stack migration

We're migrating a suite of B2B apps off a no-code platform onto a modern stack: Next.js/TypeScript, Fastify on Cloud Run, Supabase (Auth + Postgres). Looking for a partner to help expedite the build of the foundational platform (CI/CD, auth, DB, monitoring, etc.) and do a 1:1 rebuild of one smaller, existing app as a proof-of-concept, including integration with our internal CRM and other apps. This is a staff-augmentation engagement as our team will stay involved for reviews/approvals throughout, and takes over building future products once this foundation is done. We provide: design, locked V1 app rebuild scope, data model, seed data, engineering standards. You build: the platform + app rebuild to spec against APIs we expose. No access to production systems or data. Looking for: - Deep experience building the dev platform (CI/CD, golden path, DB ,etc.) based on existing specs - Strong Next.js/TypeScript/Fastify/Supabase experience - Track record rebuilding apps with verified output correctness (experience doing this from low-code to traditional is a STRONG plus) - API integration experience without backend access - Min. 4hr/day overlap with US Eastern - Strong communication, collaboration, documentation, and knowledge transfer - 3 relevant client references Note: This is a discovery-stage RFI/RFQ, not a fixed bid. We want your approach, rough cost/timeline ranges, and team fit. Full RFI with detailed requirements provided to shortlisted candidates.