Data Analyst Mock Interview: 40 SQL, Metrics & Business Questions

A data analyst interview is rarely just a SQL test.

You may be asked to

• analyze a dataset
• explain a metric
• investigate a business problem
• write SQL
• communicate findings
• choose an experiment
• challenge assumptions

That means your preparation needs both analytical and communication practice. SQL

1. How would you find duplicate records?

2. How do joins work?

3. What's the difference between INNER and LEFT JOIN?

4. How would you find the second-highest value?

5. How do window functions work?

6. How would you calculate a rolling average?

7. How would you investigate a sudden drop in a metric?

8. How would you optimize a slow query?

9. How would you handle missing data?

10. How would you validate a dataset?

Metrics

11. What metric would you use for a subscription product?

12. What is a good metric for activation?

13. How would you measure retention?

14. How would you distinguish correlation from causation?

15. What would you do if two dashboards report different numbers?

Business analysis

16. Revenue fell 10%. How would you investigate?

17. User retention dropped. What would you look at?

18. Conversion increased but revenue decreased. How is that possible?

19. How would you prioritize an analytical request?

20. What questions would you ask a stakeholder before starting an analysis?

Experimentation and statistics

21. What is an A/B test?

22. What is statistical significance?

23. What is selection bias?

24. How can an experiment produce misleading results?

25. How would you decide whether an experiment should continue?

Communication

26. How do you explain a technical result to an executive?

1. Tell me about a time your analysis changed a decision.
2. Tell me about a time your analysis was challenged.
3. Tell me about a time you found an error in your work.
4. How do you communicate uncertainty?

Behavioral

1. Tell me about a difficult stakeholder.
2. Tell me about competing priorities.
3. Tell me about a time you disagreed with a recommendation.
4. Tell me about a mistake you made.
5. Tell me about a project you are proud of.
6. Tell me about a time you had incomplete data.
7. Tell me about a difficult deadline.
8. Tell me about a time you automated a process.
9. What analytical skill are you developing?
10. Why do you want this role?

The analyst skill candidates often overlook Analysis isn't the final product. A recommendation is. You can write perfect SQL and still struggle if you cannot explain: What did the data actually tell us? What does it not tell us? What should happen next?

Practice turning every analysis into

Finding → evidence → limitation → recommendation That structure is extremely useful in interviews. [Practice a Data Analyst mock interview with Mockly]