What changes were made to middleware configuration in Laravel 11

1. Removal of the HTTP Kernel: The familiar `Kernel.php` file in the `App\Http` directory has been removed. This file previously contained the middleware configuration.

2. Middleware Configuration in `bootstrap/app.php`: The middleware configuration is now handled in the `bootstrap/app.php` file, using the `withMiddleware()` method of the `Application` class.

Example:

php
return Application::configure(basePath: dirname(__DIR__))
    ->withMiddleware(function (Middleware $middleware) {
        // Apply middleware to all routes
        $middleware->use([ExampleMiddleware::class]);

        // Use it only in the web routes
        $middleware->web([ExampleMiddleware::class]);

        // API only
        $middleware->api([ExampleMiddleware::class]);
    })
    // Other configuration
    ->create();

3. Customizing Middleware Behavior: The `Middleware` class provides methods to customize the behavior of the default middleware, such as disabling CSRF protection on specific routes or invalidating sessions on other devices.

Example:

php
->withMiddleware(function (Middleware $middleware) {
    $middleware->validateCsrfTokens(
        except: ['stripe/*']
    );

    $middleware->authenticateSessions();
})

4. Automatic Middleware Registration: With the removal of the HTTP Kernel, middleware is now automatically registered with the Laravel application. You can create a new middleware using the `artisan make:middleware` command, and it will be available for use without any additional registration.

In summary, the key changes to middleware configuration in Laravel 11 are:
- Removal of the HTTP Kernel file
- Middleware configuration moved to the `bootstrap/app.php` file
- Ability to customize middleware behavior using the `Middleware` class
- Automatic registration of middleware, eliminating the need for manual registration

This shift towards a more centralized and customizable middleware configuration aims to simplify the application structure and provide more flexibility in managing middleware in Laravel 11 projects.