Your question is Troubleshooting Linux Performance. 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).
Explain how you would troubleshoot a performance issue in a Linux server.
Describe how you would organize the investigation, identify whether the bottleneck is CPU, memory, disk, network, or an application process, and reduce operational risk while making changes. Include the evidence you would collect, how you would communicate status, and how you would validate recovery and prevent recurrence.