Pre-prod load, soak, stress, and spike testing against the NFR register's performance targets. Validates capacity sizing, surfaces bottlenecks before production, and produces the perf-test-soak-pass evidence for the production_go_live gate. QA Engineer + Platform/SRE co-own this; SA contributes the scenarios; Backend Developer interprets results. Use whenever NFR-bearing changes are being released, when capacity sizing needs validation, when investigating perf regressions, or when establishing perf-test cadence.
