// RESTful routing
GET    /api/users        → List users
GET    /api/users/:id    → Get user
POST   /api/users        → Create user
PUT    /api/users/:id    → Update user
DELETE /api/users/:id    → Delete user

// Naming conventions
/api/v1/resource           // Versioned API
/api/resource/:id/subresource  // Nested resource
/api/resource?filter=value     // Query params

src/
├── components/    ← UI components
├── pages/         ← Page components
├── hooks/         ← Custom hooks
├── utils/         ← Helper functions
├── services/      ← API calls
├── stores/        ← State management
├── types/         ← TypeScript types
└── assets/        ← Static assets

app/
├── (auth)/        ← Auth routes group
├── api/           ← API routes
├── dashboard/     ← Dashboard pages
├── layout.tsx     ← Root layout
└── page.tsx       ← Home page

function routeFile(filename, purpose) {
  // By extension
  if (filename.endsWith('.test.ts')) {
    return 'alongside source';
  }
  
  // By purpose
  const routes = {
    'component': 'src/components/',
    'page': 'src/pages/',
    'hook': 'src/hooks/',
    'util': 'src/utils/',
    'type': 'src/types/',
    'api': 'src/api/'
  };
  
  return routes[purpose] || 'src/';
}