The current daily_revenue pipeline computes today only, runs once a night, and freezes each day's nu
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
The current daily_revenue pipeline computes today only, runs once a night, and freezes each day's number forever. A late mobile event from five days ago arrives today and lands nowhere because the pipeline never looks back. The section's simplest workable fix is the seven-day rerun window: every morning, recompute the last seven days, not just today. The pattern requires three things: an idempotent write (re-running produces the same answer, not duplicates), partition-level overwrite by event_date (yesterday's row gets replaced, not added to), and source data retained for at least the window length. Set the rerun window: add an orchestrator that schedules a daily run with a seven-day rerun window in its name, and replace the destination with a lakehouse format whose partition overwrite makes the rerun idempotent.
How This Interview Works
- Read the vague prompt (just like a real interview)
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