React Performance: JS Perf — Cache Property Access. Keywords: cache property loop. Platform: React/Next.js. Description: Cache object property lookups in hot paths. Do: Cache values before loops. Don't: Access nested properties in loops. Good Example: const val = obj.config.settings.value; for (...) process(val). Bad Example: for (...) process(obj.config.settings.value). Severity: Low-Medium.