performance▌

Memoization, code splitting, and virtualization patterns for optimizing React application performance. \n \n Covers four core optimization techniques: memoization (React.memo, useMemo, useCallback), code splitting with lazy/Suspense, virtualization for large lists, and state management strategies to minimize render cascades \n Includes React 18+ concurrent features (useTransition, useDeferredValue) for improved responsiveness and perceived performance \n Provides profiling workflow using React D

'Run Lighthouse audits locally via CLI or Node API, parse and interpret reports, and set performance budgets. Use when measuring site performance, understanding Lighthouse scores, setting up budgets, or integrating audits into CI. Triggers on: lighthouse, run lighthouse, lighthouse score, performance audit, performance budget. Do NOT use for fixing specific performance issues (use perf-web-optimization or core-web-vitals) or Astro-specific optimization (use perf-astro).'

'Optimize web performance: bundle size, images, caching, lazy loading, and overall page speed. Use when site is slow, reducing bundle size, fixing layout shifts, improving Time to Interactive, or optimizing for Lighthouse scores. Triggers on: web performance, bundle size, page speed, slow site, lazy loading. Do NOT use for Core Web Vitals-specific fixes (use core-web-vitals), running Lighthouse audits (use perf-lighthouse), or Astro-specific optimization (use perf-astro).'

'Astro-specific performance optimizations for 95+ Lighthouse scores. Covers critical CSS inlining, compression, font loading, and LCP optimization. Use when optimizing Astro site performance, improving Astro Lighthouse scores, or configuring astro-critters. Do NOT use for non-Astro sites (use perf-web-optimization or core-web-vitals) or running Lighthouse audits (use perf-lighthouse).'

Optimize Core Web Vitals (LCP, INP, CLS) for better page experience and search ranking. Use when asked to "improve Core Web Vitals", "fix LCP", "reduce CLS", "optimize INP", "page experience optimization", or "fix layout shifts". Focuses specifically on the three Core Web Vitals metrics. Do NOT use for general web performance (use perf-web-optimization), Lighthouse audits (use perf-lighthouse), or Astro-specific optimization (use perf-astro).

Optimizes application performance by identifying and fixing bottlenecks based on profiling data.

Conducts multi-axis code review to assess code quality across correctness, readability, architecture, security, and performance before merging changes.

Tests in real browsers using Chrome DevTools MCP for debugging and inspecting web applications.

Safe read-only PostgreSQL audit workflow using https://postgresaudit.com/ for least-privilege setup, report interpretation, and remediation planning.

nextjs15-performance