Deploy & Maintain AI Voice Agent Backend (Node.js/TypeScript, Express, Retell AI, Supabase

I'm building an AI phone receptionist for Swiss trades companies (electricians, plumbers, HVAC). The AI answers inbound calls, classifies urgency, books appointments, and escalates emergencies via WhatsApp. The codebase is already written and production-ready — I need a developer to deploy it, test it end-to-end, and support ongoing iterations. What's already done Complete TypeScript/Express.js backend (~10 files) Retell AI webhook integration (voice provider) Google Calendar booking integration (adapter pattern, extensible) WhatsApp emergency escalation with retry logic Full documentation and setup guides What I need from you Deploy the backend to Railway or Render Set up Supabase as the database Connect and test all integrations live (Retell AI, Google Calendar API, WhatsApp) Run end-to-end test calls and fix any bugs Ongoing availability for iterations (paid hourly or per milestone) Requirements Strong Node.js/TypeScript and Express.js experience Experience with webhooks and third-party API integrations Familiarity with Railway/Render and Supabase (or similar) Bonus: experience with voice AI platforms (Retell, Vapi, Bland) Clear communicator — I'm non-technical, so you must explain things simply