Load tests verify expected traffic, stress tests explore beyond capacity, spike tests test sudden demand changes, and endurance tests reveal leaks or gradual degradation. Each test should have a hypothesis and measurable acceptance criteria.

Use realistic request mixes, payload sizes, authentication, cache states, data distributions, and geographic latency. Validate the load generators themselves so they do not become the bottleneck. Measure throughput, p95/p99 latency, errors, resource saturation, queue age, database lock waits, and dropped work.

A high request rate is not a successful result if requests fail silently or asynchronous work never completes. Test cold and warm cache behavior separately and compare against a stable baseline.