Your question is Metrics for Product Success. 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).
What metrics would you define for this product? Explain how you would select a primary success metric, supporting metrics, and guardrails. Clarify assumptions about the product, user journey, business objective, and available data before proposing the metric framework.