The economics of e-commerce performance are well-established: Walmart reported a 2% increase in conversions for every 1-second improvement in page load time. Google found that a 0.1-second improvement in mobile page speed correlates with a 10% increase in retail revenue. Every 100ms matters. Despite this, performance optimization remains one of the most neglected aspects of e-commerce development.
Core Web Vitals as the Performance Framework
Google's Core Web Vitals — Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift — provide a standardized framework for measuring and improving e-commerce performance. LCP measures perceived load speed, INP measures interactivity, and CLS measures visual stability. Optimizing for these three metrics addresses the user experience dimensions most correlated with business outcomes.