Your question is Diagnosing a Sudden Metric Drop. 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).
A critical metric has suddenly dropped by 20%; walk me through your step-by-step diagnostic process.
Explain how you would first validate the metric and determine whether the movement is real or caused by data quality, definition, or pipeline issues. Then describe how you would decompose the change across relevant dimensions, test competing hypotheses, quantify business impact, and communicate findings. State the data sources, checks, visualizations, and decision criteria you would use, along with guardrail metrics and recommended next steps.