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Top 41 MongoDB Interview Questions and Answers

01/Oct/2020 | 10 minutes to read

QFLES is listing some Essential MongoDB Interview Questions and Answers for Freshers and mid level of Experienced Professionals prepared by Industry Experts. All answers for these MongoDB interview questions are given based on standard documents and tried to explain in simple and easiest way.

Best Answers to MongoDB Interview Questions

1. What is MongoDB, Why to use it and When to use it?

2. What are the advantages of using MongoDB?

3. What is the difference between NoSQL and RDBMS?

4. Give some real world use cases of MongoDB.

5. Explain key components of MongoDB Architecture.

6. How to update MongoDB field using the value of another field?

7. Explain Replication.

8. How data is stored in MongoDB?

9. Explain Index. How many types of Index MongoDB provides?

10. What is Covered Queries in MongoDB? Give an example.

11. How to perform SQL Join equivalent in MongoDB?

12. What is Data Modeling in MongoDB?

13. What is the purpose of schema validation in MongoDB?

14. How to query MongoDB with "like" similar to SQL?

15. How to find objects between two dates in MongoDB?

16. How to achieve primary key - foreign key relationships in MongoDB?

17. Explain Aggregation in MongoDB.

18. How to get all the keys in a collection?

19. Explain the concept of Sharding in MongoDB?

20. What is collation in MongoDB?

21. Give an example of MongoDB CRUD operations.

22. Explain Bulk write operations.

23. How to ensure consistency in MongoDB?

24. How collection is different from a table?

25. How MongoDB handle caching?

26. How to create a database and a collection in MongoDB?

27. How to see what indexes exist on a collection?

28. How does an index affect database performance?

29. How does sharding affect concurrency in MongoDB?

30. Write an query condition comparing two fields in MongoDB.

31. How will you update objects in document's array in MongoDB?

32. How to retrieve only queried or filtered element in an object array?

33. How will you query for documents where array size is greater than 1 in MongoDB?

34. What is oplog in MongoDB?

35. How MongoDB ensures High availability?

36. Is MongoDB schemaless Database system?

37. Explain MongoDB relationships.

38. Explain Primary and secondary replica sets in MongoDB.

39. How will you Find document with array that contains a specific value in MongoDB?

40. How will you remove an array element?

41. How to update multiple documents with a single command in MongoDB?

Some General Interview Questions for MongoDB

1. How much will you rate your self in MongoDB?

When you attend an interview, Interviewer may ask you to rate your self in specific Technology like MongoDB, So It's depend on your knowledge and work experience in MongoDB.

2. What challenges did you face while working on MongoDB?

This question may be specific to your technology and completely depends on your past work experience. So you need to just explain the challenges you faced related to MongoDB in your Project.

3. What was your role in last Project related to MongoDB?

It's based on your role and responsibilities assigned to you and what functionality you implemented using MongoDB in your project. This question is generally asked in every interview.

4. How much experience do you have in MongoDB?

Here you can tell about your overall work experience on MongoDB.

5. Have you done any MongoDB Certification or Training?

It's depend on candidate like you have done any MongoDB training or certification. Certifications or trainings are not essential but good to have.


We have covered some frequently asked MongoDB Interview Questions and Answers to help you for your Interview. All these Essential MongoDB Interview Questions are targeted for mid level of experienced Professionals and freshers.
While attending any MongoDB Interview if you face any difficulty to answer any question please write to us at Our IT Expert team will find the best answer and will update on portal. In case if we find any new MongoDB questions, we will update the same here.

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