Yesterday's Crown
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
A cost dashboard needs each date paired with the previous day's top-spending service, with daily service totals rounded to two decimals before they are compared. Where several services tie for the highest spend, include all of them, and skip any date without a prior day on record. Return the billing day, the service name, and that total amount.
Summary
Every dawn inherits the spending of the day before.
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