The Notification That Paid Off
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
We ran a push notification campaign starting one day after each user's first transaction. How many users went on to buy new products they hadn't purchased on their first day? Users who only re-bought the same items or never made additional purchases don't count. Return a single count.
Summary
The message went out to thousands. A smaller number actually bit.
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