Monthly Cohort Retention

A medium SQL interview practice problem on DataDriven. Write and execute real sql code with instant grading.

Domain

SQL

Difficulty

medium

Seniority

mid

Problem

Build a cohort retention analysis. Users are grouped by the month they signed up. For each signup cohort, calculate what fraction of users were active in each subsequent month. A user is active in a month if they have at least one session during that month. Return the cohort month, the months since signup, and the retention rate.

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