30 most useful Drupal 8 interview questions

1. What is the use of cookie Domain?

2. How Drupal user serves session?

3. Where does session references get stored in Drupal 8?

4. What would be the execution order of following hooks? hook_init, hook_page_alter, hook_block_xxx

5. How Module works in Drupal 8?

6. What is render cache? How is it useful?

7. What is event subscriber in Drupal 8?

8. How singleton classes helps in database connection in Drupal 8?

9. How will you establish connection with Redis (NOSQL) in Drupal 8?

10. What are annotations in Drupal 8? what are the uses?

11. How drupal 8 is secured ?

12. Have you done any contribution on d.o?

13. What is decoupled Drupal?

14. How does routing work in Drupal 8?

15. If you have multi-site Drupal 8 setup how can you share the data between sites without using a table prefix

16. Write a program to reverse the STRING (INDIA) without using any built-in function of PHP

17. How can we inject dependency or services in a custom class.

18. Which is better hooks or events : https://www.previousnext.com.au/blog/alter-or-dispatch-drupal-8-events-versus-alter-hooks?

19. How can we add a new form element to a form with ajax of another form element (You need to have form rebuild and the add that form element in the form alter and not the ajax callback)?

20. You must have seen utf character for special characters like "%#$%@,"in title field in drupal 8 views how can we remove it?

21. How can we handle rollback of database for any transaction in drupal 8?

22. Which service to use for fetching queue data?

23. How to create a custom serialiser in drupal 8?

24. What are the modules used to migrated Drupal 7 to Drupal 8?

25. Suppose you are on the last page of admin/content and you delete all the content exists on the last page now you see the page you are on is empty, how would you resolve it.  

26. Suppose you are using third party IDP, once user logs in into IDP user gets redirected on callback URL, now you have to trigger rules to send a welcome mail, how would you do that (provide detailed step)

27. When and How to Use domain access module? https://www.srijan.net/blog/guide-domain-access-drupal

28. How to configure xdebug with Drupal 8 docker container? please send the steps in details

29. How encryption happens in Drupal 8 for user password?

30 What will happen if you enable Drupal cache even you already have redis/memcache configured with your Drupal 8 application?


If you struggle to find the solution for any of the above questions, post your answer to get that validated.