app/
├── Actions/              # Single-purpose action classes
├── Contracts/            # Interfaces (DI)
├── DTOs/                 # Data transfer objects
├── Enums/                # PHP 8.1+ enums
├── Events/               # Domain events
├── Http/
│   ├── Controllers/      # Thin controllers
│   ├── Middleware/       # Request filters
│   ├── Requests/         # Form validation
│   └── Resources/        # API transformations
├── Jobs/                 # Queued jobs
├── Listeners/            # Event handlers
├── Models/               # Eloquent models only
├── Policies/             # Authorization
├── Providers/            # Service registration
├── Repositories/         # Data access layer
└── Services/             # Business logic

public function __construct(
    private readonly UserServiceInterface $userService,
) {}

public function register(): void
{
    $this->app->bind(UserServiceInterface::class, UserService::class);
    $this->app->singleton(CacheService::class);
}

php artisan make:provider CustomServiceProvider
php artisan make:command ProcessOrders

$debug = env('APP_DEBUG', false);
$config = config('app.name');