| name | ops-performance |
| description | Performance analysis for Expo + serverless backend projects. Runs Lighthouse audits, bundle size analysis, and k6 load tests. |
| allowed-tools | ["Bash","Read"] |
Ops: Performance
Analyze application performance.
Argument: $ARGUMENTS — analysis type (lighthouse, bundle, k6, all; default: all) and optional target environment
Path Convention
- Frontend: Current project directory (
.)
- Backend:
${BACKEND_DIR:-../backend-v2} — set BACKEND_DIR in .claude/settings.local.json if your backend is elsewhere
Discovery
- Read frontend
package.json for lighthouse:check, export:web, analyze:bundle scripts
- Read backend
package.json for k6:* scripts
- Read
e2e/constants.ts or .env.* files for environment URLs
Lighthouse Audit
Against Local
npx lighthouse http://localhost:8081 \
--output=json \
--output-path=./lighthouse-local.json \
--chrome-flags='--headless --no-sandbox'
Against Deployed Environment
Discover frontend URLs from e2e/constants.ts or .env.* files:
npx lighthouse https://{env_url} \
--output=json \
--output-path=./lighthouse-{env}.json \
--chrome-flags='--headless --no-sandbox'
LHCI (Lighthouse CI — uses project config)
bun run lighthouse:check
Parse Lighthouse Results
cat lighthouse-{env}.json | jq '{
performance: .categories.performance.score,
accessibility: .categories.accessibility.score,
bestPractices: .categories["best-practices"].score,
seo: .categories.seo.score,
fcp: .audits["first-contentful-paint"].displayValue,
lcp: .audits["largest-contentful-paint"].displayValue,
tbt: .audits["total-blocking-time"].displayValue,
cls: .audits["cumulative-layout-shift"].displayValue,
si: .audits["speed-index"].displayValue
}'
Bundle Analysis
Full Analysis (export + source-map-explorer)
bun run export:web && bun run analyze:bundle
Quick Size Check
bun run export:web
echo "=== Total Bundle Size ==="
du -sh dist/
echo ""
echo "=== Largest JS Files ==="
find dist -name "*.js" -exec ls -lhS {} + 2>/dev/null | head -20
k6 Load Tests
Discover available k6 scripts from the backend package.json (matching k6:*).
Smoke Test (minimal load, verify endpoints work)
cd "${BACKEND_DIR:-../backend-v2}"
bun run k6:smoke
Load Test (normal traffic simulation)
cd "${BACKEND_DIR:-../backend-v2}"
bun run k6:load
Stress Test (push beyond normal capacity)
cd "${BACKEND_DIR:-../backend-v2}"
bun run k6:stress
Spike Test (sudden traffic burst)
cd "${BACKEND_DIR:-../backend-v2}"
bun run k6:spike
Docker-based k6 (no local k6 install needed)
cd "${BACKEND_DIR:-../backend-v2}"
bun run k6:docker:smoke
bun run k6:docker:load
Output Format
Lighthouse Scores
| Metric | Score | Rating |
|---|
| Performance | 0.85 | GOOD |
| Accessibility | 0.92 | GOOD |
| Best Practices | 0.88 | GOOD |
| SEO | 0.95 | GOOD |
Core Web Vitals
| Metric | Value | Threshold | Status |
|---|
| FCP (First Contentful Paint) | 1.2s | < 1.8s | PASS |
| LCP (Largest Contentful Paint) | 2.1s | < 2.5s | PASS |
| TBT (Total Blocking Time) | 150ms | < 200ms | PASS |
| CLS (Cumulative Layout Shift) | 0.05 | < 0.1 | PASS |
Bundle Size
| Category | Size | Notes |
|---|
| Total dist/ | 4.2 MB | |
| Largest chunk | 1.1 MB | vendor.js |
k6 Results
| Metric | Value |
|---|
| Requests/sec | 450 |
| Avg response time | 120ms |
| p95 response time | 350ms |
| Error rate | 0.1% |
Include recommendations for any metrics that fall below thresholds.
