The Session Stitcher
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
- L5
Interview Prompt
Our event pipeline doesn't track sessions natively. Given a stream of page-view events with user_id and timestamp, define a session as a sequence where no two consecutive events are more than 30 minutes apart. Assign a session_id to each event, then compute the average session duration and average pages per session.
Summary
Page views without sessions are just noise.
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