# Performance Optimization (Laravel)

> Query optimization, N+1 problem, eager loading, lazy loading, caching strategies, database indexing, profiling tools

- 22 interview questions
- Senior
- [Interview Questions: Laravel](https://sharpskill.dev/en/technologies/laravel/interview-questions.md)

## 1. What is the N+1 problem in Laravel?

**Answer**

The N+1 problem occurs when Eloquent executes one query to retrieve a collection, then an additional query per item to load a relationship. This multiplies database accesses and severely degrades performance at scale. Using eager loading with with() loads all relationships in a single additional query instead of N queries.

## 2. Which method should be used to solve the N+1 problem when loading relationships?

**Answer**

The with() method performs eager loading which loads relationships in a single additional query. Rather than executing one query per model when accessing the relationship, all relationships are loaded upfront. This drastically reduces the number of SQL queries and improves performance.

## 3. What is the difference between eager loading and lazy loading?

**Answer**

Eager loading loads relationships immediately with the main query via with(), while lazy loading loads relationships on demand upon first access. Lazy loading can cause the N+1 problem if relationships are accessed in a loop. Eager loading is recommended when relationships will be used to avoid multiple queries.

## 19 more questions available

- What is the role of Cache::remember() in Laravel?
- What is the difference between Cache::remember() and Cache::rememberForever()?

Sign up for free: https://sharpskill.dev/en/login

## Other Laravel interview topics

- [PHP Basics](https://sharpskill.dev/en/technologies/laravel/interview-questions/php-basics.md): 25 questions, Junior
- [PHP OOP Essentials](https://sharpskill.dev/en/technologies/laravel/interview-questions/php-oop-essentials.md): 20 questions, Junior
- [Composer & Autoloading](https://sharpskill.dev/en/technologies/laravel/interview-questions/composer-autoloading.md): 18 questions, Junior
- [Laravel Fundamentals](https://sharpskill.dev/en/technologies/laravel/interview-questions/laravel-fundamentals.md): 20 questions, Junior
- [Laravel Routing](https://sharpskill.dev/en/technologies/laravel/interview-questions/laravel-routing.md): 20 questions, Junior
- [Blade Templates](https://sharpskill.dev/en/technologies/laravel/interview-questions/blade-templates.md): 18 questions, Junior
- [Request & Response](https://sharpskill.dev/en/technologies/laravel/interview-questions/request-response.md): 20 questions, Junior
- [Eloquent ORM Basics](https://sharpskill.dev/en/technologies/laravel/interview-questions/eloquent-orm-basics.md): 22 questions, Junior
- [Eloquent Relationships](https://sharpskill.dev/en/technologies/laravel/interview-questions/eloquent-relationships.md): 25 questions, Mid-Level
- [Migrations & Schema Builder](https://sharpskill.dev/en/technologies/laravel/interview-questions/database-migrations.md): 20 questions, Mid-Level
- [Validation & Forms](https://sharpskill.dev/en/technologies/laravel/interview-questions/validation-forms.md): 22 questions, Mid-Level
- [Authentication](https://sharpskill.dev/en/technologies/laravel/interview-questions/authentication.md): 20 questions, Mid-Level
- [Authorization & Policies](https://sharpskill.dev/en/technologies/laravel/interview-questions/authorization-policies.md): 18 questions, Mid-Level
- [API Resources & Authentication](https://sharpskill.dev/en/technologies/laravel/interview-questions/api-resources-authentication.md): 26 questions, Mid-Level
- [Middleware](https://sharpskill.dev/en/technologies/laravel/interview-questions/middleware.md): 18 questions, Mid-Level
- [Service Container & DI](https://sharpskill.dev/en/technologies/laravel/interview-questions/service-container-di.md): 20 questions, Mid-Level
- [Queues & Jobs](https://sharpskill.dev/en/technologies/laravel/interview-questions/queues-jobs.md): 22 questions, Mid-Level
- [Events & Listeners](https://sharpskill.dev/en/technologies/laravel/interview-questions/events-listeners.md): 18 questions, Mid-Level
- [Notifications & Mail](https://sharpskill.dev/en/technologies/laravel/interview-questions/notifications-mail.md): 20 questions, Mid-Level
- [File Storage](https://sharpskill.dev/en/technologies/laravel/interview-questions/file-storage.md): 18 questions, Mid-Level
- [Testing & PHPUnit](https://sharpskill.dev/en/technologies/laravel/interview-questions/testing-phpunit.md): 24 questions, Mid-Level
- [Caching](https://sharpskill.dev/en/technologies/laravel/interview-questions/caching.md): 18 questions, Mid-Level
- [Livewire & Inertia](https://sharpskill.dev/en/technologies/laravel/interview-questions/livewire-inertia.md): 20 questions, Mid-Level
- [Eloquent Advanced](https://sharpskill.dev/en/technologies/laravel/interview-questions/eloquent-advanced.md): 24 questions, Senior
- [Repository Pattern](https://sharpskill.dev/en/technologies/laravel/interview-questions/repository-pattern.md): 20 questions, Senior
- [Laravel Packages](https://sharpskill.dev/en/technologies/laravel/interview-questions/laravel-packages.md): 20 questions, Senior
- [Security Best Practices](https://sharpskill.dev/en/technologies/laravel/interview-questions/security-best-practices.md): 22 questions, Senior
- [Laravel Octane](https://sharpskill.dev/en/technologies/laravel/interview-questions/laravel-octane.md): 18 questions, Senior
- [Laravel Distributed Systems](https://sharpskill.dev/en/technologies/laravel/interview-questions/laravel-distributed-systems.md): 22 questions, Senior
- [Observability & Monitoring](https://sharpskill.dev/en/technologies/laravel/interview-questions/observability-monitoring.md): 20 questions, Senior
- [Deployment & DevOps](https://sharpskill.dev/en/technologies/laravel/interview-questions/deployment-devops.md): 20 questions, Senior

---

Source: SharpSkill (https://sharpskill.dev), tech interview preparation for your real stack.
HTML version of this page: https://sharpskill.dev/en/technologies/laravel/interview-questions/performance-optimization