Next.js App Router Patterns That Scale

The App Router changed how we build Next.js applications. Here are patterns I've found work well at scale.

File Organization

src/
├── app/           # Routes
├── components/    # Shared components
│   ├── ui/        # Base UI components
│   └── features/  # Feature-specific
├── lib/           # Utilities and data
└── hooks/         # Custom hooks

Server vs Client Components

Default to Server Components. Only use Client Components when you need interactivity or browser APIs.

Data Fetching

Fetch data at the highest level possible and pass it down. Use React's cache() for deduplication.

Loading States

Create loading.tsx files for route segments. Use Suspense boundaries for granular loading states.

Error Handling

Implement error.tsx for route-level error boundaries. Handle expected errors gracefully.

These patterns have helped me build maintainable Next.js applications that perform well at scale.