Monthly Cloud Cost Forecast Error
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 want a naive forecast model for monthly cloud costs. Sum cloud cost amounts at a monthly level. Use the previous month's total as the forecast for the current month, then calculate the absolute percentage error versus actual. Show year-month, actual cost, forecasted cost, and percentage error.
Summary
The forecast was off. By how much?
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