Your question is Troubleshoot Production Failures. 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).
How would you troubleshoot a failing service in production?
Explain how you would confirm the incident, reduce customer impact, isolate the fault, coordinate responders, and decide whether to roll back or apply a fix. Include the evidence you would collect, the stakeholders you would update, and the follow-up actions you would require after recovery.