Token Churn Rate
A medium SQL mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- SQL
- Difficulty
- medium
- Seniority
- L4
Interview Prompt
Compute churn for API tokens in September 2026. Churn rate is the difference between tokens active on September 1 and tokens active on September 30, divided by the count on September 1. A token is active if it was issued on or before the target date and either has no expiration or expires on or after that date. Return a single churn rate.
Summary
Tokens come and go. How fast is the revolving door?
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write your sql solution with real code execution
- Get instant feedback and a hire/no-hire decision