Designing for Performance

Performance is a design constraint, not an afterthought you bolt on before launch. Start with Core Web Vitals — Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift — because these are the metrics Google actually uses to judge your site, and the ones your visitors feel even if they've never heard the names. Measure with Lighthouse before you optimize anything; guessing at bottlenecks wastes time. In practice, the biggest wins are usually the boring ones: serve images at the size they're actually displayed, load fonts without blocking render, and avoid shipping JavaScript for parts of the page that don't need interactivity. Set a performance budget per page and treat a regression like a bug, not a nice-to-have.