Senior Full-Stack Developer — Custom Booking Flow (C# Azure + Stripe + Bókun/Regiondo API)

We run a live experiences platform that shows last-minute activity deals from suppliers. The platform is fully built and in production — backend API on Azure, Supabase database, React frontend. We now need to replace our third-party booking widgets with our own branded checkout flow. What needs to be built: Custom availability calendar on the frontend (React) Participant selector and guest details form Stripe payment integration using Stripe Elements POST /api/bookings endpoint in C# Azure Functions with two booking models: API model — creates booking directly in Bókun or Regiondo via their REST APIs Manual model — logs the booking in our database and sends a confirmation email to the supplier Monthly booking summary per supplier for reconciliation and payout tracking Booking confirmation page The codebase is clean, well structured and already in production. Full documentation and onboarding will be provided. You are not building from scratch — you are extending an existing professional codebase. Bókun and Regiondo services are already built and can be used as reference. Tech stack: Backend: C# Azure Functions (.NET isolated worker) Database: Supabase (PostgreSQL) Frontend: React / TypeScript Payments: Stripe Booking APIs: Bókun REST API, Regiondo REST API Requirements: Strong C# / .NET experience — non-negotiable Previous Stripe integration experience — please include examples REST API integration experience React / TypeScript Available to start immediately Timeline: 2-3 weeks. Senior developers only. Please include in your proposal examples of similar Stripe or booking API integrations you have built, your estimated timeline, and your fixed price.