A load test should represent realistic request mixes, payload sizes, think time, authentication, cache hit rates, and data distributions. Define whether the goal is baseline capacity, stress behavior, spike response, endurance, or recovery testing.

Increase load gradually and record throughput, latency percentiles, errors, CPU, memory, garbage collection, database saturation, connection pools, queue depth, and downstream latency. A system may show rising latency before throughput collapses; that is often a sign of saturation.

Avoid unrealistic tests that warm every cache, use tiny datasets, or run from a single client that becomes the bottleneck. Compare runs with a known baseline and change one major variable at a time. Production canaries and gradual rollout complement, but do not replace, controlled load testing.