Rolling Revenue Average
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
Compute a 3-month rolling average of total revenue from transactions, excluding refunds (negative amounts). For each month, the average uses the current month and the two preceding months. Show year-month in YYYY-MM format and the rolling average, sorted chronologically. The first two months will not be true 3-month averages.
Summary
Smooth out the revenue bumps. The trend matters more.
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