No Dead Months
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're building a leaderboard of ad campaigns, but a campaign only earns a spot if it drew at least one click in every calendar month it was active. Among the campaigns that clear that bar, order them by their single heaviest month of revenue, lowest peak first, and return just the campaign name.
Summary
Every month it ran, it landed a click. Among those, find the ones whose worst month of spend stayed lowest.
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