Performance Pass

Backend checklist:

• API
  • Pagination defaults for list endpoints
  • Avoid N+1 patterns; verify includes/joins
  • Add caching headers or server caching where appropriate
  • Validate payload sizes and streaming for large responses
• DB
  • Verify indexes align with query predicates and sort order
  • Check migration/backfill impacts (locks, write amplification)
  • Watch for chatty queries
• Runtime
  • Avoid unnecessary allocations in hot paths
  • Ensure async usage is correct (no sync-over-async)
• Guardrails
  • Add perf-focused tests/benchmarks only if repo already uses them

Frontend checklist (React):

• Rendering
  • Avoid unnecessary re-renders; use memoization only where it helps
  • Verify list virtualization for large lists if relevant
• Data fetching
  • Avoid duplicate requests; handle loading/error states cleanly
  • Ensure caching strategy is consistent (query libs, cache keys)
• Bundling
  • Avoid adding heavy dependencies without justification
  • Ensure code splitting for large new routes/features if repo supports it

Verification:

• Run build and measure obvious regressions (build output, bundle warnings)
• Smoke test core flows affected
• If repo has profiling tools/scripts, run them and report results

Finish with:

• Potential perf risks identified
• Changes made (if any) to mitigate
• Commands run + results
• Follow-ups (monitoring, dashboards, load testing)