Laravel Vue.js Full-Stack Best Practices: SOLID Principles, MVC Architecture & Eloquent Guide

**Do:** Adopt SOLID principles in OOP for maintainable code, using dependency injection via Laravel's service container.
**Example:**
```php
// Good: Inject dependencies
class UserService {
    public function __construct(private UserRepository $repo) {}
}
```

**Don't:** Duplicate code; instead, iterate and modularize reusable logic.
**Example:**
```php
// Bad: Copy-paste validation
// Good: Extract to trait or service
trait Validatable {
    public function validateUser(array $data): bool { /* logic */ }
}
```

**Do:** Use descriptive names and follow Laravel's directory structure (e.g., app/Http/Controllers).
**Example:**
```php
// File: app/Http/Controllers/UserController.php
class UserController extends Controller { /* methods */ }
```

**Don't:** Ignore strict typing; always declare(strict_types=1) and leverage PHP 8.2+ features like readonly properties.
**Example:**
```php
<?php
declare(strict_types=1);
class User {
    public function __construct(public readonly string $name) {}
}
```

**Do:** Implement PSR-12 standards, Eloquent ORM, migrations, and request validation with Form Requests.
**Example:**
```php
// Migration
public function up(): void {
    Schema::create('users', function (Blueprint $table) {
        $table->id()->index();
    });
}
// FormRequest
class StoreUserRequest extends FormRequest {
    public function rules(): array { return ['name' => 'required']; }
}
```

**Don't:** Handle errors manually; use Laravel's exception handling, logging, and try-catch for predictable issues.
**Example:**
```php
try {
    $user = User::findOrFail($id);
} catch (ModelNotFoundException $e) {
    Log::error('User not found', ['id' => $id]);
    throw new CustomUserException('User missing');
}
```

**Do:** Organize Vue.js with Vite, src/components folder, lazy-loaded routes via Vue Router, and modular Pinia stores.
**Example:**
```vue
<!-- src/components/UserList.vue -->
<script setup>
const store = useUserStore();
const users = store.users;
</script>
```

**Don't:** Skip form validation; integrate Vuelidate and style with TailwindCSS/PrimeVue.
**Example:**
```vue
<script setup>
import { useVuelidate } from '@vuelidate/core';
const rules = { name: required };
const v$ = useVuelidate(rules, state);
</script>
```

**Do:** Secure APIs with Laravel Passport, CSRF, caching, queues, and testing via PHPUnit/Dusk.
**Example:**
```php
Route::middleware('auth:api')->group(function () {
    Route::apiResource('users', UserController::class);
});
// Cache
Cache::remember('users', 3600, fn() => User::all());
```

**Don't:** Neglect scalability; use events/listeners, job queues, scheduling, and API versioning.
**Example:**
```php
// Event
Event::listen(UserCreated::class, SendWelcomeEmail::class);
// Schedule
$schedule->command('users:cleanup')->daily();