# A daily orders pipeline ran green every night last week Canonical URL: Domain: Pipeline Design ยท Difficulty: medium ## Problem A daily orders pipeline ran green every night last week. Finance noticed Friday that revenue dropped 12 percent on Tuesday and stayed low. The cause: a Kafka partition silently dropped events for six hours; the pipeline read every event that was present and exited zero. Operational success and semantic failure coexisted. The section's point is that green orchestrator runs do not prove the data is correct. Spot the silent failure by adding a quality gate between the transform and the mart, plus a paging destination so the gate's verdict reaches a human. ## Related - [All practice problems](https://datadriven.io/problems) - [Mock interview mode](https://datadriven.io/interview/a-daily-orders-pipeline-ran-green-every-night-last-week-fin-a6df0ee9) - [System Design Interview Questions](https://datadriven.io/data-engineering-system-design) - [Data Engineering Interview Prep Guide](https://datadriven.io/data-engineer-interview-prep) - [Daily Challenge](https://datadriven.io/daily) --- Source: DataDriven (https://datadriven.io). 100% free data engineering interview prep. Live code execution against Postgres 16, Python 3.11, and Spark sandboxes. No paywall, no premium tier, no signup gate.