What metrics do you focus on when analyzing performance test results?
- metrics
- response time
- throughput
- analysis
Answer it first, then compare. Nothing here is saved or scored.
Model answer
Key metrics: (1) Response time percentiles: p50 (median), p95, p99. Averages hide outliers. (2) Throughput: requests per second the system can handle. (3) Error rate: percentage of failed requests under load. (4) Resource utilization: CPU, memory, disk I/O, network. (5) Connection counts: active connections, connection pool usage. (6) Apdex score: user satisfaction metric combining fast, tolerable, and frustrated requests. (7) Saturation point: the load level where response times start climbing exponentially.
What interviewers listen for
- Workload modellingYou design the load shape from product traffic, not from tool defaults.
- Percentile literacyYou read p50/p95/p99 separately and explain why each matters.
- Bottleneck triageYou correlate metrics across application, database, and infrastructure layers.
- Capacity instinctsYou can translate a soak test into a sizing or scaling recommendation.