| name | benchmark |
| description | Performance baseline and regression detection -- page performance, API latency, build times, and before/after comparison. |
| origin | ECC |
Benchmark -- Performance Baseline and Regression Detection
Measure and compare performance metrics to detect regressions.
When to Use
- Before and after a PR to measure performance impact
- Setting up performance baselines for a project
- When users report "it feels slow"
- Before a launch -- ensure you meet performance targets
- Comparing your stack against alternatives
Modes
Mode 1: Page Performance
Measures real browser metrics: LCP, CLS, INP, FCP, TTFB, total page weight, JS bundle size, CSS size, image weight, network request count.
Mode 2: API Performance
Benchmarks API endpoints: hit each endpoint 100 times, measure p50/p95/p99 latency, track response size, test under 10 concurrent requests.
Mode 3: Build Performance
Measures development feedback loop: cold build time, HMR time, test suite duration, TypeScript check time, lint time, Docker build time.
Mode 4: Before/After Comparison
/benchmark baseline # saves current metrics
# ... make changes ...
/benchmark compare # compares against baseline
Output:
| Metric | Before | After | Delta | Verdict |
|---|
| LCP | 1.2s | 1.4s | +200ms | WARN |
| Bundle | 180KB | 175KB | -5KB | BETTER |
| Build | 12s | 14s | +2s | WARN |
Storage
Stores baselines in .ecc/benchmarks/ as JSON. Git-tracked so the team shares baselines.
Integration
- CI: run
/benchmark compare on every PR
- Pair with
/canary-watch for post-deploy monitoring
- Pair with
/browser-qa for full pre-ship checklist
