The Churner Who Came Back
A hard Data Modeling mock interview question on DataDriven, with an AI interviewer who asks follow-up questions and a hire or no-hire decision at the end.
- Domain
- Data Modeling
- Difficulty
- hard
- Seniority
- L5
Interview Prompt
Design a data model for a global subscription business with hundreds of millions of subscribers on several plan tiers across regions, where every upgrade, downgrade, pause, cancel and re-subscribe is kept with the moment it took effect, so a subscriber who comes back still has their earlier cancel on record. Finance and product analytics will use it for churn analysis, plan mix by tier, and the monthly recurring revenue each subscriber was paying, by region, at any point in time.
Summary
They cancelled. They came back. The report has to tell both stories correctly.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Draw your data model on the schema canvas: tables, keys and relationships
- Answer the interviewer's follow-up questions, then get a hire or no-hire decision