Day 48 of #100DayOfCode — Deployment I: Deploy Backend

Earlier, on Day 40 , I built the backend for my auth system. Then on Day 44 , I improved it by adding TypeScript and Zod for type safety and validation. Today (Day 48), the goal was simple: 👉 Deploy the backend to production using Vercel Why Vercel? I chose Vercel for backend deployment because: Zero-config deployment (especially smooth with GitHub) Global edge network → fast response times Automatic CI/CD on every push Easy environment variable management Works well for serverless Node.js APIs Step-by-Step Backend Deployment Step 1: Add vercel.json Create a vercel.json file in the root directory: { "version" : 2 , "builds" : [ { "src" : "dist/server.js" , "use" : "@vercel/node" } ], "routes" : [ { "src" : "/(.*)" , "dest" : "dist/server.js" } ] } This tells Vercel: Where your built backend lives ( dist/server.js ) How to route all incoming requests Step 2: Export Your App Properly Make sure the main server is exported correctly. In server.ts, after app.listen() : app . listen ( PORT ,