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Drupal is a powerful open-source CMS used by enterprises, governments, and large-scale websites. Whether you’re applying for a Drupal developer, themer, or architect role, mastering key concepts is essential.

To help you ace your interview, we’ve compiled the top 21 Drupal interview questions—covering basics, theming, module development, and performance optimization.

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Top 21 Drupal Interview Questions & Answers

1. What is Drupal?

Drupal is a content management system (CMS) written in PHP. It’s highly flexible, scalable, and used for building complex websites.

2. What are the key features of Drupal?

✔ Modular architecture – Extend functionality with modules
✔ Theming system – Customize site appearance
✔ User management – Granular permissions
✔ Multilingual support – Built-in translation
✔ API-first approach – Works with REST/GraphQL

3. What is a Drupal node?

A node is a basic content unit in Drupal (e.g., article, blog post, or page). Nodes can have fields, revisions, and translations.

4. Explain Drupal’s hook system.

Hooks allow modules to alter Drupal’s behavior. Examples:

• hook_menu() – Define menu items
• hook_form_alter() – Modify forms
• hook_node_view() – Change node display

5. What is a Drupal module?

A module adds functionality to Drupal. Core modules come with Drupal, while contrib modules (like Views, Webform) are downloaded from Drupal.org.

6. What is the difference between Drupal 8, 9, and 10?

• Drupal 8 introduced Symfony framework, Twig templating.
• Drupal 9 removed deprecated code, improved performance.
• Drupal 10 introduced CKEditor 5, modern PHP support.

7. What is the Drupal theme layer?

Themes control how Drupal looks. Key components:

• Twig templates (.html.twig)
• CSS/JS aggregation
• Responsive design

8. How do you create a custom module in Drupal?

1. Create a folder in /modules/custom.
2. Add a .info.yml file (metadata).
3. Define routing in .routing.yml.
4. Use controllers or hooks for logic.

9. What is the Views module?

Views is a query builder that fetches and displays content (lists, grids, tables).

10. How do you optimize Drupal performance?

✔ Enable caching (Page, Dynamic Page Cache)
✔ Use CDN for assets
✔ Optimize images (with ImageAPI Optimize)
✔ Database tuning (MySQL/PostgreSQL)

11. What is Drush?

Drush is a command-line tool for Drupal administration (e.g., clearing cache, updating modules).

12. How do you debug Drupal?

• Drupal Devel module (dpm() for debugging)
• Xdebug with PHPStorm
• Watchdog logs (/admin/reports/dblog)

13. What are Drupal entities?

Entities are structured data types:

• Nodes
• Users
• Taxonomy terms
• Custom entities

14. How do you implement multilingual support?

• Enable Language module
• Use Content Translation
• Configure Interface Translation

15. What is the Configuration Management system?

Drupal’s CMI stores site configuration in YAML files (e.g., content types, views) for easy deployment.

16. How do you secure a Drupal site?

✔ Update core/modules regularly
✔ Use HTTPS
✔ Limit user permissions
✔ Enable Security Kit (SecKit)

17. What is the difference between Blocks and Content Types?

• Blocks are reusable UI components (e.g., banners).
• Content Types define structured content (e.g., Blog, Product).

18. How do you create a custom theme?

1. Define a .info.yml file.
2. Override templates (e.g., node--article.html.twig).
3. Add CSS/JS in libraries.yml.

19. What is Dependency Injection in Drupal?

DI is a design pattern where services are passed to a class rather than created inside it (used in Drupal 8+).

20. How do you handle database migrations?

• Migrate API (core in Drupal 8+)
• Drush migrate commands

21. What’s new in Drupal 10?

• CKEditor 5 (better WYSIWYG)
• Modern PHP 8.1+ support
• Improved frontend tools (Claro admin theme)

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Benefits of Mastering Drupal

✅ High Demand – Enterprises need Drupal experts.
✅ Scalability – Handles large traffic (e.g., NASA, Tesla).
✅ Flexibility – Customize for any use case.
✅ Strong Community – Free modules & support.

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FAQ Section

1. Is Drupal better than WordPress?

• Drupal is better for complex, scalable sites.
• WordPress is easier for blogs/small sites.

2. What’s the hardest part of Drupal development?

Learning curve (especially Symfony concepts in Drupal 8+).

3. How do I stay updated with Drupal?

• Follow Drupal.org
• Join DrupalCon
• Subscribe to Drupal newsletters

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Conclusion

Drupal is a powerful CMS for developers who need flexibility, security, and scalability. By mastering these top 21 Drupal interview questions, you’ll be ready for technical discussions and coding challenges.

Next Steps:

• Build a Drupal portfolio site
• Contribute to Drupal.org
• Practice custom module/theme development

Good luck with your interview! 🚀