Your question is Diagnose an Integration Pipeline Issue. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You're supporting a customer-facing data integration and need to troubleshoot why data is missing, delayed, or incorrect. You want a clear way to isolate whether the problem is in extraction, transformation, loading, scheduling, or downstream mapping.
What steps would you take to diagnose a customer issue with an integration?