Explain the Laravel request lifecycle.

 

Difficulty: Intermediate
Interview Level: Mid-Level

One of the most important Laravel interview topics is understanding what happens after a user sends an HTTP request.

Consider:

GET /products/10

The request enters Laravel through the application's public entry point.

Conceptually:

Browser
   ↓
Web Server
   ↓
public/index.php
   ↓
Application Bootstrap
   ↓
HTTP Kernel / Middleware Pipeline
   ↓
Router
   ↓
Middleware
   ↓
Controller
   ↓
Application Logic
   ↓
Response
   ↓
Middleware
   ↓
Browser

---

Step 1 — Web server

Usually Nginx or Apache receives the request.

For example:

https://example.com/products/10

The web server directs the request toward Laravel's public entry point.

Laravel applications are normally configured so the web server's document root points to:

project/public

rather than exposing the entire project.

---

Step 2 — Entry point

Laravel's public entry point is:

public/index.php

This starts the application.

The framework loads the Composer autoloader:

require __DIR__.'/../vendor/autoload.php';

and bootstraps the Laravel application.

---

Step 3 — Application bootstrap

Laravel initializes the application and its configuration/environment.

Examples include:

.env
config/*
service providers
container
routing
middleware

---

Step 4 — Middleware

Middleware can inspect or modify requests.

Example:

public function handle($request, Closure $next)
{
    if (!$request->user()) {
        return redirect('/login');
    }

    return $next($request);
}

Middleware is commonly used for:

• Authentication
• Authorization
• CSRF protection
• Rate limiting
• Logging
• Request modification
• CORS
• Maintenance mode

---

Step 5 — Routing

Laravel matches the URL to a route.

Route::get('/products/{product}', [
    ProductController::class,
    'show'
]);

For:

/products/10

Laravel can resolve:

product = 10

and, with implicit model binding, potentially resolve the corresponding Product model.

---

Step 6 — Controller

The controller receives the request.

public function show(Product $product)
{
    return view('products.show', compact('product'));
}

The controller should generally coordinate the request rather than contain enormous business logic.

---

Step 7 — Database

The application might use Eloquent:

$product = Product::findOrFail($id);

Laravel then communicates with MySQL through the configured database connection.

---

Step 8 — Response

Laravel can return:

return view('products.show', compact('product'));

or:

return response()->json($product);

or:

return redirect()->route('products.index');

---

Why request lifecycle matters in interviews

Knowing the lifecycle helps diagnose problems.

For example:

Route doesn't execute
        ↓
Check route registration

Controller doesn't execute
        ↓
Check middleware / route matching

Database query fails
        ↓
Check Eloquent / DB configuration

Authentication fails
        ↓
Check guards / middleware

Wrong output
        ↓
Check controller / resource / view

A senior developer should understand where a problem occurs rather than randomly modifying code.