Monthly Cohort Retention
Company: Coupang
Role: Data Scientist
Category: Data Manipulation (SQL/Python)
Difficulty: medium
Interview Round: Technical Screen
Overview: This question evaluates practical SQL skills in user retention analysis, specifically the ability to build a monthly cohort retention table from raw activity logs. It tests date truncation, window-based grouping, and aggregation logic commonly required in data science and analytics roles. The question targets applied SQL proficiency and product analytics thinking under real-world schema constraints.
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