Improving site performance by shipping more CSS

GitHub engineers recently shared an unconventional approach to web performance: shipping more CSS to improve site speed. While conventional wisdom suggests minimizing CSS to reduce payload size, the team discovered that by inlining critical styles and leveraging modern browser caching mechanisms, they could significantly reduce layout shifts and improve the Largest Contentful Paint (LCP). By analyzing the critical path, the team moved away from aggressive code splitting that often caused secondary network requests, opting instead to deliver a larger, unified stylesheet. This strategy ensures that the browser has all necessary styling information immediately upon parsing the HTML, eliminating the need for render-blocking requests. The results demonstrate that performance optimization is not always about reducing file size, but rather about optimizing the browser's rendering pipeline and reducing network round-trips. This case study provides valuable insights for developers looking to balance bundle size with perceived performance.