The Slow Fade
A medium SQL mock interview question on DataDriven, with an AI interviewer who asks follow-up questions and a hire or no-hire decision at the end.
- Domain
- SQL
- Difficulty
- medium
- Seniority
- L4
Interview Prompt
We review signup retention one calendar year at a time: users fall into cohorts by the month they signed up, and we want to know what share of each cohort logged at least one session in the months from signup through that year's December. Report each cohort, the number of months since signup, and that active share.
Summary
They all arrive together. Watch the room empty, month by month.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write and run your SQL against a real database
- Answer the interviewer's follow-up questions, then get a hire or no-hire decision