Covers the essentials for speeding up modern web apps: React code splitting with lazy loading, webpack bundle optimization, service worker caching strategies, and Core Web Vitals monitoring with the Performance Observer API. Includes practical configs for nginx compression and image optimization with responsive srcsets. The monitoring code is updated for INP instead of the deprecated FID metric, which matters if you're tracking against current standards. Good reference when you're trying to get LCP under 2.5s or need to explain to stakeholders why bundle sizes matter. The checklist format makes it easy to audit what you've already done versus what's still dragging down your Lighthouse score.
npx skills add https://github.com/secondsky/claude-skills --skill web-performance-optimization