Who Stayed
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
Retention wants the most loyal visitors of all time: the users with the longest streaks of consecutive calendar days that had at least one session, counting only the days on or before 2026-08-10. Surface the three longest streak lengths along with every user who reached them.
Summary
Day after day after day. Who kept coming back?
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