A streaming aggregation tumbles in 5-minute event-time windows with bounded out-of-orderness waterma
A medium Pipeline Design mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- Pipeline Design
- Difficulty
- medium
Interview Prompt
A streaming aggregation tumbles in 5-minute event-time windows with bounded out-of-orderness watermark using 60-second lag. The product team needs to catch slightly-late events (mobile retries up to an hour) but cannot hold engine state forever. The section's worked configuration is allowed lateness of 60 minutes plus a dead-letter destination for events past the budget; events on time fire once, slightly late events fire again with updated totals, very late events route to the dead-letter sink for the next-day reconciliation pass. Walk the timeline by adding two pieces to the canvas: an annotation on the aggregation transform stating the allowed-lateness budget, and a dead-letter storage destination wired from the aggregation for events past the budget.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write your pipeline design solution with real code execution
- Get instant feedback and a hire/no-hire decision