vercel-migration-deep-dive

# Vercel Migration Deep Dive ## Overview Migrate applications to Vercel from Netlify, AWS (Lambda/CloudFront/S3), Cloudflare Workers, or traditional hosting. Covers configuration mapping, DNS cutover, feature parity validation, and incremental migration with the strangler fig pattern. ## Current State !`vercel --version 2>/dev/null || echo 'Vercel CLI not installed'` !`cat package.json 2>/dev/null | jq -r '.name // "no package.json"' 2>/dev/null || echo 'N/A'` ## Prerequisites - Access to current hosting platform - Git repository with application source - DNS management access for domain cutover - Vercel account (Pro recommended for production) ## Instructions ### Step 1: Configuration Mapping **From Netlify:** | Netlify | Vercel Equivalent | |---------|-------------------| | `netlify.toml` | `vercel.json` | | `_redirects` / `_headers` | `vercel.json` redirects/headers | | Netlify Functions (`netlify/functions/`) | API routes (`api/`) | | Netlify Edge Functions | Edge Middleware or Edge Functions | | `NETLIFY_ENV` | `VERCEL_ENV` | | Deploy previews | Preview deployments (automatic) | | Branch deploys | Branch preview URLs | ```json // Netlify _redirects → vercel.json // FROM: /old-page /new-page 301 // TO: { "redirects": [ { "source": "/old-page", "destination": "/new-page", "permanent": true } ] } // Netlify _headers → vercel.json // FROM: /* X-Frame-Options: DENY // TO: { "headers": [ { "source": "/(.*)", "headers": [ { "key": "X-F...