The Space Between Us
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
We run an ad platform and want to measure how much any two users overlap in the campaigns that actually earned revenue from them. For each pair of users sharing at least one such campaign, report how many campaigns earned from both and the overlap ratio: campaigns that earned from both divided by campaigns that earned from either.
Summary
Every viewer lives inside a world of campaigns. Measure how much two of those worlds are really one.
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