Performance Fundamentals and Troubleshooting Questions

Core skills for identifying, diagnosing, and resolving general performance problems across applications and systems. Topics include establishing baselines and metrics, using monitoring and profiling tools to determine whether issues are CPU bound, memory bound, input output bound, or network bound, and applying systematic troubleshooting workflows. Candidates should be able to prioritize fixes, recommend temporary mitigations and long term solutions, and explain when to escalate to specialists. This canonical topic covers general performance awareness, common diagnostic tools, and basic remediation approaches for slow systems and resource exhaustion.

EasyBehavioral

0 practiced

Tell me about a time you handled a performance incident in production. Use the STAR format: Situation, Task, Action, Result. Focus on how you diagnosed the problem, what short-term mitigation you implemented, and what long-term changes you pushed afterwards.

HardTechnical

0 practiced

Propose an automated remediation pipeline for performance incidents: detection → classification → runbook selection → automated remediation → human-in-loop escalation. For each stage, describe implementation choices, failure modes, and safety checks to avoid harmful automation.

MediumTechnical

0 practiced

In Kubernetes, a pod shows CPU throttling (cpu.cfs_throttled_periods increased). Describe why throttling happens, how it affects latency, and three actions you can take to investigate and mitigate the impact on the service.

MediumTechnical

0 practiced

Write a short Bash script or systemd timer configuration to perform log rotation for an application that produces large JSON logs, ensuring rotations do not lose logs and old logs are compressed. Explain assumptions and atomicity considerations.

EasyTechnical

0 practiced

You have the following log snippet from a backend service:

[2025-06-01T12:34:10Z] WARN request_id=abc123 duration_ms=1200 upstream=database timeout_ms=1000[2025-06-01T12:34:11Z] WARN request_id=def456 duration_ms=1400 upstream=cache timeout_ms=500

What immediate conclusions can you draw about the type of performance problem, and what next steps would you take to validate and prioritize fixes?

Unlock Full Question Bank

Get access to hundreds of Performance Fundamentals and Troubleshooting interview questions and detailed answers.

Join thousands of developers preparing for their dream job.