Data Analyst interview questions
The 7 questions that actually come up, each with what a strong answer covers. These are not scripts to memorise — interviewers can tell — they are the shape of the answer that gets a yes.
7 questionsData Analyst career guide →
Write a query returning each customer's second-highest order value.
What a strong answer coversWindow functions (ROW_NUMBER/DENSE_RANK) — practice these until fluent; ranking problems open most analyst interviews.
Revenue dropped 12% week over week. How do you investigate?
What a strong answer coversDecompose: segment (region, product, channel), then mix vs rate, then data-quality check BEFORE narrative. Structure beats speed.
Explain p-values to a non-technical stakeholder.
What a strong answer coversA plain-words analogy without the word 'probability the null…'. They are testing communication, and most candidates fail it by being technically precise and humanly useless.
When is an average the wrong summary?
What a strong answer coversSkewed distributions (income, order values) → median/percentiles; mention how outliers and mix shifts mislead trend lines.
How do you know a dashboard metric can be trusted?
What a strong answer coversLineage: where the number comes from, freshness, definition ownership, reconciliation against a source of truth. 'The dashboard says so' is the wrong answer.
Design an A/B test for a checkout change. What can go wrong?
What a strong answer coversUnit of randomisation, sample size/power, novelty effects, peeking. Naming peeking usually wins the exchange.
SQL: what is the difference between WHERE and HAVING?
What a strong answer coversRow filter vs aggregate filter — and show you know the execution order that explains it.