All at Once
A hard SQL mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- SQL
- Difficulty
- hard
- Seniority
- L5
Interview Prompt
For every API token ever issued, find the largest number of tokens that were active at the same time during this token's own active window, and the earliest date that peak was reached. A token counts as active from its issued date through the day before it expires, and a token with no expiration is treated as still active.
Summary
How many tokens were alive at the same time?
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