Kings of the Calendar
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
- L4
Interview Prompt
We publish a monthly leaderboard of the best-selling products for an online marketplace, where selling is measured by total units sold in each calendar month. For every month, return the top 10 products with their total units sold and standing, counting only completed sales by dropping any transaction with a negative `total_amount` (those are refunds), with the oldest month first.
Summary
Every month has a winner.
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