Who Stayed
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
Group users into signup cohorts by the month they registered, and track how each cohort holds up over the following months. For every month from signup onward, report the share of the cohort who had at least one session that month, labeled by how many months after signup it falls.
Summary
Every signup is a promise. See how many kept it, month after month.
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