nextjs

<essential_principles>

How Next.js 16 Works

Next.js 16 uses the App Router with React Server Components by default. It introduces Cache Components with the "use cache" directive, Turbopack as the default bundler, and React 19.2 features.

1. Server-First Rendering

Components are Server Components by default. They:

• Run only on the server
• Can directly fetch data (no useEffect needed)
• Cannot use hooks, event handlers, or browser APIs
• Reduce client JavaScript bundle

Add 'use client' only when you need interactivity, state, or browser APIs.

2. BFF Pattern (Backend for Frontend)