Data Analyst Interview Questions and Answers (2026)

Every question below opens to a full page: a quick answer you could give under pressure, what the interviewer is really probing, how to structure your response, a first-person example answer, and the follow-ups that usually come next. Work through your weakest category first.

Prefer one long read? The full data analyst interview guide covers preparation, process and salary talk in a single article.

SQL

What is the difference between an inner join and a left join, and whe...Answer + example What is a window function, and how does it differ from a GROUP BY?Answer + example Explain the difference between ROW_NUMBER, RANK, and DENSE_RANK.Answer + example When do you use WHERE versus HAVING?Answer + example When would you use a CTE instead of a subquery?Answer + example How would you find and remove duplicate records in a table?Answer + example How would you calculate month over month growth in SQL?Answer + example What is a fan out join, and how would you spot one in your own query?Answer + example

Statistics

What does a p value actually mean, and what does it not tell you?Answer + example A stakeholder says users who use feature X retain better, so we shoul...Answer + example What is Simpson's paradox, and have you seen it in real data?Answer + example When would you report the median instead of the mean?Answer + example

Experimentation

How would you design an A/B test for a new checkout flow?Answer + example

Analysis

How would you build a cohort retention analysis, and what would you l...Answer + example

Modeling

Why are reporting tables usually denormalized when transactional data...Answer + example

Scenario

Daily active users dropped 20% overnight. How do you investigate?Answer + example Two dashboards show different numbers for revenue and both owners ins...Answer + example A product team asks you to define a north star metric for their featu...Answer + example Your A/B test finishes and the result is not statistically significan...Answer + example An executive asks for a dashboard to see how the business is doing. H...Answer + example You find an error in a report that already went to the leadership tea...Answer + example

Tooling

When do you move an analysis out of SQL and into Python?Answer + example What is a semantic layer, and what problem does it solve for an analy...Answer + example

Visualization

How do you decide what chart type to use for a given result?Answer + example

Process

How do you make sure an analysis you ran three months ago can be repr...Answer + example

These are the classics. Your data analyst posting has its own. Paste your actual job description into the free Question Predictor and get the 20 questions that role is most likely to ask, with what each one is really probing.

Predict my questions

Walking into this interview soon? GhostPilot listens to your live call, spots the question the moment it is asked, and puts a structured answer on your screen in real time. Try it on your next mock, or grab a $29 Session Pass, no subscription, for the real thing.

See how it works

SQL