Yesterday's Crown
A hard SQL mock interview question on DataDriven, with an AI interviewer who asks follow-up questions and a hire or no-hire decision at the end.
- Domain
- SQL
- Difficulty
- hard
- Seniority
- L4
Interview Prompt
A cloud cost dashboard shows, for each billing day, which service spent the most the day before, where a service's spend on a day is the total of its charges that day. Return each billing day with that prior-day top service, its spend, and the prior day's total spend across all services.
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 and run your SQL against a real database
- Answer the interviewer's follow-up questions, then get a hire or no-hire decision