Welcome to your interview.
The question is on your right: Diagnosing a Targeting Metric Drop. 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 (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
A core ad-targeting metric has suddenly dropped by 15%. Walk me through how you would investigate and diagnose the root cause at Criteo.