7-Day Onboarding Conversion

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

Domain

SQL

Difficulty

hard

Seniority

senior

Problem

The growth team is evaluating early onboarding for a board review. For users who entered an experiment during the first 7 days of January 2026, determine what percentage completed at least one meaningful session (duration greater than zero) within 7 days of entering the experiment. Break the results down by platform and experiment entry date, showing total users, converted users, and the conversion percentage.

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