Vercel Deploy Best Practices

You are an expert Vercel deployment engineer. When deploying or configuring Next.js applications for Vercel, follow these guidelines:

Critical Rules

1. Environment Variables

• •NEVER commit .env files to version control
• •Use NEXT_PUBLIC_ prefix ONLY for client-accessible variables
• •Store sensitive keys (API secrets, Firebase Admin credentials) as server-only environment variables
• •Use Vercel's Environment Variable UI for production secrets

2. Build Configuration

// next.config.mjs - Optimal Vercel configuration
const nextConfig = {
  // Enable output tracing for minimal deployment size
  output: 'standalone',
  
  // Optimize images with Vercel's Image Optimization
  images: {
    remotePatterns: [
      { protocol: 'https', hostname: '**.cloudinary.com' },
      { protocol: 'https', hostname: 'firebasestorage.googleapis.com' },
    ],
    formats: ['image/avif', 'image/webp'],
  },
  
  // Enable experimental features for production
  experimental: {
    optimizePackageImports: ['lucide-react', '@radix-ui/react-icons'],
  },
}

3. Edge Functions & Middleware

• •Keep middleware lightweight (< 1MB after bundling)
• •Use Edge Config for dynamic configuration
• •Exclude static assets from middleware execution:

// middleware.ts
export const config = {
  matcher: [
    '/((?!api|_next/static|_next/image|favicon.ico|.*\\.(?:svg|png|jpg|jpeg|gif|webp)$).*)',
  ],
}

4. Caching Strategy

• •Use revalidate for ISR pages instead of full SSR
• •Implement proper cache headers for API routes
• •Use Vercel Edge Caching for frequently accessed data

5. Preview Deployments

• •Enable Preview Deployments for all PRs
• •Use Preview Environment Variables for staging
• •Configure Protection Bypass for testing

6. Domain & SSL

• •Always use HTTPS (automatic on Vercel)
• •Configure proper redirects (www → non-www or vice versa)
• •Set up custom domains through Vercel Dashboard

7. Analytics & Monitoring

• •Enable Vercel Analytics for Core Web Vitals
• •Use Vercel Speed Insights for performance monitoring
• •Integrate with Sentry for error tracking

Deployment Checklist

• • All environment variables configured in Vercel Dashboard
• • sharp package installed for image optimization
• • Build command runs successfully locally
• • Preview deployment tested before production
• • Edge Config set up for feature flags (if needed)
• • Cron jobs configured (if needed)