Your question is Owning a High-Stakes Production Bug. 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).
Tell me about a time you had to debug and troubleshoot a difficult production issue in a codebase you owned or were responsible for. How did you isolate the root cause, communicate along the way, and what was the outcome?