Your question is Diagnosing a Sudden KPI 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).
If a core business KPI suddenly drops by 15% overnight, what is your step-by-step framework for diagnosing the root cause? Explain how you would first validate the measurement and data pipeline, then distinguish a real business change from an instrumentation or reporting issue. Describe how you would decompose the movement, prioritize hypotheses, communicate findings, and define follow-up actions.