Data Analytics Interview Questions

What Interviewers Are Actually Testing

Most candidates prepare for the SQL part. Fewer prepare for the business case part. Almost none prepare for the communication part. The best interviews show you can do all three — diagnose a data problem, write the query, interpret the result, and tell a non-technical stakeholder what it means for their decision.

Core SQL Interview Questions

Almost every data analyst interview includes a SQL section. Practise these on real datasets rather than toy examples — it shows in how you frame your answers.

• "Write a query to find the top 5 customers by total revenue in the last 30 days." Use window functions and show you understand date filtering and aggregation.
• "Find users who placed an order but never made a second purchase." Tests LEFT JOIN logic and subquery thinking — a classic retention analysis question.
• "Given a sessions table and an orders table, calculate conversion rate by acquisition channel." Tests JOIN construction and metric definition.
• "Explain the difference between RANK() and DENSE_RANK() with an example." Shows depth of SQL knowledge beyond basic queries.

Business Case & Metric Questions

These questions test whether you can move from data to a decision. Structure every answer around: the metric that matters, the data you would use, the analysis you would run, and the recommendation you would make.

• "Our weekly active users dropped 15% last week. Walk me through how you'd investigate." Show your diagnostic sequence: product changes, seasonal patterns, data quality, funnel breakdown by segment.
• "How would you measure the success of a new feature we just launched?" Anchor on the business outcome the feature is meant to drive, not just adoption metrics.
• "We have two marketing channels with similar CAC. How do you decide where to invest more?" This is about LTV, retention, payback period — not just acquisition cost.

Dashboard & Visualisation Questions

If the role involves Tableau, Looker, or Power BI, expect questions about design decisions — not just tool familiarity. The best answers explain why you chose a visualisation type, not just what it shows.

• "Walk me through a dashboard you've built and the decisions it supported."
• "When would you use a bar chart vs. a line chart? Give a real example."
• "How do you decide what to exclude from a dashboard?"

How to Answer When You Don't Know

The strongest candidates don't pretend to know things they don't. When you encounter an unfamiliar question, say so — then walk through how you would approach finding the answer. That diagnostic thinking is often what interviewers are evaluating. Saying "I'd start by looking at X and Y, then narrow down from there" is far better than guessing.