LARAVEL Interview Questions and Answers

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🌱 Basic Laravel Interview Questions & Answers

1. What is Laravel? Why do we use it?

Answer:
Laravel is a PHP framework based on MVC (Model-View-Controller) architecture. It provides elegant syntax, built-in features like routing, authentication, ORM, and caching that help developers build web applications faster and with less effort.

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2. What are the main features of Laravel?

Answer:

• Eloquent ORM (database handling)

• Blade template engine

• Artisan CLI

• Routing system

• Middleware

• Authentication and Authorization

• Migrations and Seeders

• Task scheduling & Queues

• RESTful API support

• Built-in Security (CSRF, XSS protection, encryption)

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3. What is MVC architecture in Laravel?

Answer:

• Model → Handles data and database logic.

• View → Displays data (UI).

• Controller → Handles user requests, processes data via Model, and returns responses via View.
  Laravel follows MVC to separate concerns and keep code organized.

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4. What is Artisan in Laravel?

Answer:
Artisan is Laravel’s command-line tool. It helps automate repetitive tasks like creating controllers, models, migrations, seeding, clearing cache, etc.
Example:

php artisan make:controller UserController
php artisan migrate

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5. What are Service Providers in Laravel?

Answer:
Service providers are the central place of Laravel application bootstrapping. They register services, bindings, and event listeners. For example, AppServiceProvider, AuthServiceProvider.

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6. What is Middleware in Laravel?

Answer:
Middleware is a filter for HTTP requests.

• Example: auth middleware checks if a user is logged in before accessing certain routes.

• We can also create custom middleware for logging, role-checking, etc.

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7. Explain the difference between GET, POST, PUT, and DELETE in Laravel routes.

Answer:

• GET → Retrieve data (e.g., view a page).

• POST → Submit new data (e.g., create user).

• PUT → Update existing data (e.g., update profile).

• DELETE → Delete existing data (e.g., delete record).

Example:

Route::get('/users', 'UserController@index');
Route::post('/users', 'UserController@store');
Route::put('/users/{id}', 'UserController@update');
Route::delete('/users/{id}', 'UserController@destroy');

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8. What is the difference between Session and Cache?

Answer:

• Session → Stores user-related temporary data (e.g., login info, shopping cart).

• Cache → Stores frequently accessed data to improve performance (e.g., query results, API responses).

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9. How does Laravel handle security?

Answer:

• CSRF Protection → Prevents cross-site request forgery using _token.

• XSS Protection → Escapes output in Blade {{ $data }}.

• SQL Injection Protection → Eloquent & Query Builder use prepared statements.

• Password Hashing → bcrypt and argon2.

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10. How do you install Laravel?

Answer:

1. Install Composer.

2. Run command:

composer create-project laravel/laravel myApp

or

laravel new myApp

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Great 🚀 Let’s continue with the Intermediate Level Laravel Interview Questions & Answers (11–20).

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⚡ Intermediate Laravel Interview Questions & Answers

11. What is Eloquent ORM?

Answer:
Eloquent is Laravel’s built-in ORM (Object-Relational Mapper). It allows interaction with the database using models instead of raw SQL queries.
Example:

$users = User::all();   // Select * from users
$user = User::find(1);  // Select * from users where id = 1

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12. What are the differences between hasOne, hasMany, belongsTo, and belongsToMany relationships?

Answer:

• hasOne → One-to-One relationship. (User → Profile)

• hasMany → One-to-Many relationship. (User → Posts)

• belongsTo → Inverse of hasOne/hasMany. (Post → User)

• belongsToMany → Many-to-Many relationship. (User ↔ Roles)

Example:

// User hasOne Profile
public function profile() { return $this->hasOne(Profile::class); }

// User hasMany Posts
public function posts() { return $this->hasMany(Post::class); }

// Post belongsTo User
public function user() { return $this->belongsTo(User::class); }

// User belongsToMany Roles
public function roles() { return $this->belongsToMany(Role::class); }

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13. What are Migrations in Laravel? Why do we use them?

Answer:
Migrations are version control for databases. They allow us to create, update, and share database structures with code instead of manual SQL.
Example:

php artisan make:migration create_users_table
php artisan migrate

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14. What is the difference between Query Builder and Eloquent?

Answer:

• Query Builder → Works with raw SQL queries, lightweight, faster for complex queries.

• Eloquent → Object-oriented, works with models, easier to use but slightly slower.

Example:

// Query Builder
$users = DB::table('users')->where('status', 1)->get();

// Eloquent
$users = User::where('status', 1)->get();

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15. How do you implement validation in Laravel?

Answer:
Using validate() in controllers or FormRequest.
Example:

$request->validate([
    'name' => 'required|string|max:255',
    'email' => 'required|email|unique:users',
    'password' => 'required|min:6'
]);

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16. What are Laravel Facades?

Answer:
Facades provide a static interface to classes inside the service container.
Example:

Cache::put('key', 'value', 600);  // Instead of dependency injection

Common facades: DB, Cache, Auth, Route, Storage.

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17. What are Accessors and Mutators in Eloquent?

Answer:

• Accessor → Format attribute when retrieving.

• Mutator → Modify attribute before saving.

Example:

// Accessor
public function getNameAttribute($value) {
    return ucfirst($value);
}

// Mutator
public function setPasswordAttribute($value) {
    $this->attributes['password'] = bcrypt($value);
}

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18. What is the difference between Guard and Provider in Laravel Authentication?

Answer:

• Guard → Defines how users are authenticated (session, token, API).

• Provider → Defines how users are retrieved from the database.

Example: In config/auth.php:

'guards' => [
    'web' => ['driver' => 'session', 'provider' => 'users'],
    'api' => ['driver' => 'token', 'provider' => 'users'],
],
'providers' => [
    'users' => ['driver' => 'eloquent', 'model' => App\Models\User::class],
]

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19. What are Laravel Queues and why do we use them?

Answer:
Queues allow us to run long tasks (emails, notifications, reports) in the background instead of blocking the request.
Example:

dispatch(new SendEmailJob($user));

Queue workers:

php artisan queue:work

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20. What is Dependency Injection in Laravel?

Answer:
Dependency Injection (DI) is a design pattern where Laravel automatically provides class dependencies instead of manually creating them.

Example:

class UserController extends Controller {
    public function __construct(UserRepository $userRepo) {
        $this->userRepo = $userRepo; // Automatically injected
    }
}

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Perfect 👍 Now let’s move on to the Advanced Level Laravel Interview Questions & Answers (21–30).

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🚀 Advanced Laravel Interview Questions & Answers

21. What is the Repository Pattern in Laravel?

Answer:
Repository Pattern is used to abstract the data layer. Instead of directly using Eloquent in controllers, we use repositories to separate database logic from business logic.

• Advantage → Cleaner code, easy to switch database/storage.

Example:

interface UserRepository {
    public function getAll();
}

class EloquentUserRepository implements UserRepository {
    public function getAll() {
        return User::all();
    }
}

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22. How do you handle events and listeners in Laravel?

Answer:
Events allow you to subscribe and listen for actions in your application.
Example:

php artisan make:event OrderPlaced
php artisan make:listener SendOrderEmail --event=OrderPlaced

• Event → OrderPlaced fires when an order is created.

• Listener → SendOrderEmail sends an email after the event.

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23. What are Laravel Jobs and Workers?

Answer:

• Job → Represents a unit of work (e.g., sending email, generating report).

• Worker → A background process that executes queued jobs.

Example:

php artisan make:job SendEmailJob
dispatch(new SendEmailJob($user));
php artisan queue:work

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24. How does Laravel handle caching? Name different cache drivers.

Answer:
Laravel provides unified API for caching.
Supported drivers:

• file

• database

• redis

• memcached

• array

Example:

Cache::put('key', 'value', 600);
$value = Cache::get('key');

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25. What is the difference between Laravel Passport and Laravel Sanctum?

Answer:

• Passport → Full OAuth2 authentication system. Best for large apps, multiple clients, third-party integrations.

• Sanctum → Lightweight API authentication using tokens/cookies. Best for single-page apps (SPA) or simple APIs.

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26. How do you implement API rate limiting in Laravel?

Answer:
Use throttle middleware.
Example in routes/api.php:

Route::middleware('throttle:60,1')->get('/user', function () {
    return auth()->user();
});

This means: max 60 requests per minute per user/IP.

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27. What are Laravel Policies and Gates?

Answer:

• Gates → Closures that determine if a user is authorized to perform an action.

• Policies → Classes that organize authorization logic around models.

Example (Gate):

Gate::define('update-post', function ($user, $post) {
    return $user->id === $post->user_id;
});

Example (Policy):

php artisan make:policy PostPolicy

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28. How do you use Laravel Observers?

Answer:
Observers allow you to listen to model events (creating, updating, deleting).
Example:

php artisan make:observer UserObserver --model=User

In UserObserver.php:

public function created(User $user) {
    Log::info('New user created: ' . $user->email);
}

Register in AppServiceProvider:

User::observe(UserObserver::class);

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29. What is the difference between composer dump-autoload and php artisan optimize?

Answer:

• composer dump-autoload → Rebuilds class map for autoloading (loads new classes).

• php artisan optimize → (In older versions) optimized config, routes, and class loading.
  👉 In Laravel 8+, optimize command is removed because auto-optimization happens automatically.

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30. How do you manage multiple database connections in Laravel?

Answer:
Define multiple connections in config/database.php:

'mysql' => [
    'driver' => 'mysql',
    'host' => env('DB_HOST', '127.0.0.1'),
    'database' => env('DB_DATABASE', 'db1'),
],
'mysql2' => [
    'driver' => 'mysql',
    'host' => env('DB_HOST2', '127.0.0.1'),
    'database' => env('DB_DATABASE2', 'db2'),
],

Use connection:

$users = DB::connection('mysql2')->table('users')->get();

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Perfect 👍 Let’s finish strong with the Expert / Practical Laravel Interview Questions & Answers (31–40).

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🔥 Expert / Practical Laravel Interview Questions & Answers

31. How do you implement a composite key in Laravel models?

Answer:
Laravel doesn’t support composite primary keys directly.
Options:

1. Use raw queries or Query Builder.

2. Override getKeyName() and primary key handling.

3. Use a community package like laravel-composite-key.

Example (manual approach):

protected $primaryKey = ['order_id', 'product_id'];
public $incrementing = false;

But usually we handle it via unique index in migrations instead of composite primary key.

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32. How do you optimize Laravel application performance?

Answer:

• Use config, route, and view caching:

  php artisan config:cache
  php artisan route:cache
  php artisan view:cache
  

• Use queues for heavy tasks.

• Optimize database queries (avoid N+1).

• Use Eager Loading in Eloquent.

• Use Redis/Memcached for caching & sessions.

• Use Octane (Swoole/RoadRunner) for faster execution.

• Optimize assets with Laravel Mix/Vite.

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33. Explain Laravel’s Service Container.

Answer:
The Service Container is a dependency injection container. It manages class dependencies and automatically injects them when needed.

Example:

app()->bind('PaymentGateway', function () {
    return new StripePaymentGateway();
});

Now, whenever you type-hint PaymentGateway, Laravel injects StripePaymentGateway.

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34. How do you schedule tasks in Laravel?

Answer:
Laravel uses the schedule() method in App\Console\Kernel.php.

Example:

protected function schedule(Schedule $schedule)
{
    $schedule->command('emails:send')->dailyAt('9:00');
}

Then set CRON job:

* * * * * php /path-to-your-project/artisan schedule:run >> /dev/null 2>&1

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35. What is the difference between load(), with(), and lazyload() in Eloquent?

Answer:

• with() → Eager loads relationship at query time.

• load() → Eager loads relationship after query execution.

• lazyload() → Loads relationship only when accessed.

Example:

$users = User::with('posts')->get();   // with()
$user = User::find(1);
$user->load('posts');                  // load()
$user->posts;                          // lazy load

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36. How do you debug queries in Laravel?

Answer:

• Enable query logging:

DB::enableQueryLog();
$users = DB::table('users')->get();
dd(DB::getQueryLog());

• Use toSql():

$query = User::where('status', 1);
dd($query->toSql());

• Use Laravel Telescope or Debugbar package.

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37. How do you prevent N+1 query problems in Laravel?

Answer:
Use Eager Loading.
Bad (N+1 problem):

$users = User::all();
foreach ($users as $user) {
    echo $user->posts->count();
}

Good (with eager loading):

$users = User::with('posts')->get();

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38. How do you use Laravel’s Broadcasting system?

Answer:
Broadcasting allows sending real-time events to clients (like WebSockets).

Steps:

1. Configure driver in .env → BROADCAST_DRIVER=pusher (or redis).

2. Create event:

   php artisan make:event OrderShipped
   

3. Implement ShouldBroadcast:

   class OrderShipped implements ShouldBroadcast {
       public $order;
       public function __construct(Order $order) { $this->order = $order; }
       public function broadcastOn() { return ['orders']; }
   }
   

4. Listen from frontend using Laravel Echo.

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39. How do you secure an API built in Laravel?

Answer:

• Use Laravel Sanctum/Passport for authentication.

• Add rate limiting with throttle middleware.

• Use CSRF protection (if session-based).

• Validate inputs using Form Requests.

• Use HTTPS (SSL).

• Hide sensitive keys in .env.

• Return consistent JSON responses with proper status codes.

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40. How would you scale a Laravel application for millions of users?

Answer:

• Use Load Balancers (Nginx/HAProxy).

• Horizontal scaling: multiple servers running Laravel.

• Use Redis/Memcached for caching & queues.

• Optimize DB (indexes, read/write splitting, replication).

• Use CDN for static assets.

• Use Laravel Horizon to manage queues.

• Use Octane for performance.

• Containerize app with Docker/Kubernetes.

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