Next.js in Production: Auth, Performance & Deployment
An expert guide to taking a Next.js App Router app to production with TypeScript — authentication done in layers (middleware, Data Access Layer, sessions with httpOnly cookies), environment variables and keeping secrets server-only, performance with next/image, next/font, dynamic imports and bundle analysis, error handling with error.tsx and not-found, and deployment on Vercel or self-hosted with standalone output — with common mistakes and exercises.