GitHub cuts SSR time by 55% by shipping more CSS upfront

GitHub 如何通过迁移 CSS Modules 将 SSR 时间降低 55%

GitHub's engineering team shares how they cut server-side rendering time by 55% by shipping more CSS upfront instead of lazy-loading it. The key insight: inline critical styles in the initial HTML so the browser doesn't wait for separate CSS downloads. They detail how they analyzed the critical rendering path, extracted above-the-fold CSS, and avoided duplication after migrating to CSS Modules. First Contentful Paint also improved. A practical case study for teams working on front-end performance or SSR optimization.