Why is design important for Core Web Vitals and page experience?

Core Web Vitals are measured outcomes of design and front-end decisions. LCP is determined by how the largest above-fold element (typically a hero image or heading) is prioritized in the loading sequence. Designers who specify oversized images without WebP compression or lazy-loading exceptions for hero assets directly cause poor LCP scores that Google penalizes in rankings.

CLS is caused by elements that shift layout after initial render: images without defined dimensions, web fonts that swap after load, or dynamically injected banners. These are design and implementation decisions. INP measures how quickly the page responds to user interactions, which depends on JavaScript efficiency influenced by component design choices. A design review process that incorporates Lighthouse scoring at the prototype stage prevents Core Web Vitals issues before they reach production.