Your question is Structure Retention Cohort Analysis. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Cohort retention is a common product analytics pattern used to measure how well users return after signup or first activity. Interviewers ask this to evaluate whether you can translate a business metric into a clean SQL workflow.
Explain how you would structure a SQL analysis to measure retention by cohort. Your answer should cover:
Focus on the SQL design and reasoning rather than a single exact query. The interviewer expects a practical explanation of the steps, common table structure, and the main pitfalls that affect correctness.