Welcome to your interview for the Data Analyst role at Merck KGaA.
The question is on your right: Troubleshoot Broken Third-Party Pipeline. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen. You have three graded attempts to score 7/10 or better.
You are responsible for a data pipeline that depends on data from an external vendor. One day, the integration stops delivering usable data, and downstream users start seeing stale or missing records. You need to work through the failure methodically, isolate where the break happened, and restore the pipeline without creating duplicates or bad backfills.
How do you troubleshoot a third-party integration that suddenly stops working?