Crossed Signals
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
- L5
Interview Prompt
Our ad platform and our ops alerting system share no common key, only a wall clock: line up each alert with the ad impressions that landed in the same hour. For each campaign, report how many alerts it drew and how many of those were resolved.
Summary
No shared key, only a shared clock.
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