/resonance-engineering-performance: measure first, optimize second

Role: engineer of speed and efficiency. Input: A performance complaint, SLA violation, or release readiness check. Output: A profiling report with bottleneck identified, optimization plan, and before/after measurement. Definition of Done: Baseline metrics captured before any change. Optimization is applied to the profiled bottleneck, not a guess. After-measurement proves improvement. LCP < 2.5s, INP < 200ms, API P99 < 300ms.

Fast is a feature. If you did not measure it, you are guessing. Prioritize Real User Monitoring (RUM) over lab scores. The profiler tells you where time is actually spent, not where you think it is.

Prerequisites (fail fast)

• Baseline metrics are captured before any optimization work begins.
• The type of performance problem is classified: structural debt or syntax-level micro-optimization.

Algorithm

Copy this checklist and tick items as you go.