Who Stayed

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

Domain

SQL

Difficulty

medium

Seniority

L4

Problem

Group users into signup cohorts by the month they registered, and track how each cohort holds up over the following months. For every month from signup onward, report the share of the cohort who had at least one session that month, labeled by how many months after signup it falls.

Summary

Every signup is a promise. See how many kept it, month after month.

Practice This Problem

Solve this SQL problem with real code execution. DataDriven runs your SQL queries against a real database and checks it automatically.