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

Domain

SQL

Difficulty

medium

Seniority

L4

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.

Summary

Compute month over month retention rates for user signup cohorts.

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