API 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
- L3
Interview Prompt
The developer experience team is measuring token churn for the platform health dashboard. Compute the fraction of all issued API tokens whose expiration date has already passed, treating tokens with no expiration as still active. Express the result as a decimal ratio, not a percentage.
Summary
Tokens come and go. What's the turnover?
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