Active User Penetration Rate
A hard SQL mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- SQL
- Difficulty
- hard
- Seniority
- L5
Interview Prompt
The product analytics team counts a user as active on a device type only when their most recent session on it falls within 30 days of the latest session recorded anywhere in the data, they have logged at least 5 sessions on that device type, and their combined session time on it reaches 10 hours (36,000 seconds). For every device type, report the share of its users who clear all three bars at once, and keep the device types where nobody qualifies so they appear with a zero rate. Return each device type with its penetration rate.
Summary
How much of the user base is actually alive?
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write your sql solution with real code execution
- Get instant feedback and a hire/no-hire decision