Describe a time you chose a non-obvious primary metric (e.g., time-per-session over total time) and were challenged by a senior stakeholder. 1) How did you prepare your defense (counter-metrics, backtests, risk analysis)? 2) What tradeoffs did you acknowledge, and what guardrails or secondary metrics did you propose? 3) How did you commit to revisiting the decision (pre-registered thresholds, stop-loss, or sunset criteria) and what did you do when early evidence contradicted your choice?