Your question is Owning a Low-Level Performance Debug. 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 a difficult systems-level or low-level performance issue—something like CPU spikes, memory pressure, I/O stalls, or latency regressions. Walk me through how you narrowed the problem, how you communicated your approach to others, and what the outcome was.