## Production Debugging: CPU Spike Incident (Open-Ended) You are on-call for a backend service. An alert fires: **CPU usage suddenly spikes** on the service’s hosts/pods and stays high. You can ask for any information you want (dashboards, time series metrics, logs, traces, recent deploys, config changes). The interviewer will provide whatever graphs/logs you request. ### Tasks 1. **Immediate mitigation:** What do you do first to reduce user impact? 2. **Triage plan:** What key questions do you ask and what metrics/logs do you inspect? 3. **Root cause analysis:** Walk through how you narrow down hypotheses to a likely root cause. 4. **Fix + verification:** How do you validate the fix and prevent regression? Assume this is a typical microservice environment (Kubernetes or VM autoscaling, load balancer, centralized logging/metrics).