Drupal 8 Interview Questions: Drupal is a free and open source content-management framework written in PHP. Some Important drupal technical interview questions and answers for Drupal developer.
Drupal Interview Questions
Latest Drupal 8 Interview Questions and Answers for Drupal developer.
Q: What Is Drupal?
Drupal is free open source CMS (content management system) written in PHP.
Q: What are main features of Drupal 8?
1. Theme:
Drupal 8 provides a new theming engine called Twig, which is PHP-based, flexible, fast, and secure.
2. Responsive:
All the built-in themes that come with Drupal 8 are responsive, along with an admin theme
3. Multilingual:
When you install Drupal 8, the first choice you need to choose a base language for the installation.

The installer will attempt to make the reasonable choice based on your browser language and should display the page in your browser language.

If you are making a multilingual site, choose one of the languages that you want to use as installation language, and preferably not English

4. Easy Authoring (CKEditor):
New Drupal 8 features bring unprecedented power into the hands of the Content Editor, with WYSIWYG editor CKEditor now bundled with the core.
5. Better Support For Accessibility:
Drupal 8 has excellent support for industry standard accessibility technologies, like WAI-ARIA.

ARIA Live Announcements API and TabManager are significant improvements in Drupal 8, which provide control for rich Internet applications

6. Built-In Web Services:
Drupal 8 now makes it possible to use itself as a data source, and output content as JSON or XML.

You can even post data back to Drupal 8 from the front end. Hypertext Application Language (HAL) is implemented in Drupal 8 and makes exploitation of web service capabilities less painful.

7. Loading Speed:
Drupal 8 caches all entities and only loads JavaScript when necessary.

When a page is viewed, its content doesn’t need to be reloaded again.

Previously viewed content is quickly loaded from the cache. Once configured and enabled, caching is completely automatic

8. Industry Standards:
Drupal 8 aligns with the latest PHP 7 standards like PSR-4, namespaces, and traits, and uses top notch, outstanding external libraries like Composer, PHPUnit, Guzzle, Zend Feed Component, Assetic to name a few.

Meanwhile, underlying Drupal 8 features modern, object-oriented code that's the order of the day, by Symfony 2.

9. Clean URLs:
In Drupal 8, 'Clean URLs' are enabled by default and can't be disabled.

You may also like - Node Js Interview Questions
Q: What is a Module in drupal?

A module is software (code) that extends Drupal features and/or functionality

  1. Core modules - It comes by default with Drupal Installation.
  2. Contributed modules - you can download them from drupal.org
  3. CustomModules - These are custom modules created by you as per your need.
You may also like - Python Interview Questions
Q: What modules do you always recommend and why?

Following are some important modules:

  1. Views - It makes displaying lists of content very easy.
  2. Panels - Panels gives you the ability to create custom pages easily.
  3. Ctools - Chaos tool suite(Ctools) is primarily a set of APIs and tools to improve the developer experience.
  4. Token - Tokens are little snippets of text that can be used as replacement patterns. For example, if your website sends out emails and you want to add in the users name, or you want fill in a link path with a node id to provide a helpful link to content, tokens will save the day.
  5. Pathauto - Pathauto simplifies creating clean and search engine friendly URLS for the various content you add to your site.
  6. Webform - If you want to provide easy to fill out forms for the visitors of your site, the Webform module will help you out.
  7. Rules - Drupal rules will allow you to set up condition actions.
  8. Date - This is useful for allowing the easy selections of dates in content types (with a nice date popup).
  9. Quicktabs - Makes it easy to add tabbed content without having to write your own Javascript/Jquery.
  10. Libraries - Makes organizing your various libraries of functionality easy (see Jquery UI above for an example).
  11. Google Analytics - It is very helpful in tracking your website, etc.
Q: Which Design Pattern used in Drupal?

Singleton Design pattern is used in Drupal.

Q: How to add custom PHP codes in my Drupal pages or blocks?

By default, drupal does not allow adding PHP code directly inside a post or in a block.

To do this, you need to activate a drupal module called PHP filter via, Administer Site building Modules. Even though this module ships with drupal, it remains disabled by default.

Q: Which module is best for implementing Search in Drupal 8?
Solr Search module
Q: What is the use of Ctools module ?

Ctools stands for Chaos Tool Suite (ctools)

Chaos Tool Suite (ctools)
You may also like - PHP Interview Questions
Q: What is a regions in Drupal?

Regions are the main part of theme.

Example: Header, Content, Sidebar, Footer etc

Q: How can we add Regions to a Drupal Theme ?

Adding regions to a theme requires:

- Adding region meta-data to your THEMENAME.info.yml file.

- Editing your page.html.twig file and printing the new regions.

Default Regions
  1. page.header
  2. page.primary_menu
  3. page.secondary_menu
  4. page.highlighted
  5. page.help (dynamic help text, mostly for admin pages)
  6. page.content (main content of current page)
  7. page.sidebar_first
  8. page.sidebar_second
  9. page.footer
  10. page.breadcrumb
View Drupal Official Webiste
Q: What is Drush? and it's benefits?

Drush is a command line interface that help us to speed up administrative and development tasks for Drupal websites

After installing Drush, we’ll be able to perform useful actions command line.

Drush runs on Drupal 6, 7 well as 8.

Note: Drupal 8, works only with Drush 8.

Couple of task which can be be done using Drush easily are :
  1. Download Drupal
  2. Download contrib modules
  3. Install Drupal
  4. Update Drupal and contrib module versions
  5. Run updatedb
  6. Clear the cache
  7. Run cron
  8. Run Drupal with a lightweight web server
  9. Import, export and merge configuration
  10. Add users and set their roles
  11. Add permissions to roles
  12. Back up and restore Drupal
  13. Copy your database and files to a remote server
  14. Compile twig templates
You may also like - WordPress Interview Questions
Q: What is a node in Drupal?

A node is any piece of individual content, such as a page, poll, article etc.

Q: What is a blocks in Drupal?

Blocks are the pieces of content that can be rendered anywhere on your Drupal website.

Q: What is a taxonomy in Drupal?

Taxonomy, a powerful core module, gives your sites use of the organizational keywords known in other systems as categories, tags, or metadata.

It is used to classify the content of the website.

You may also like - React Js Interview Questions