Josh Black and the Primer Design System team at GitHub migrated from CSS-in-JS to CSS Modules to improve site performance, addressing challenges with slow initial page loads and server-side rendering. Using an incremental migration strategy with feature flags and visual regression tests, they completed the transition by December 2024, achieving 55% faster server-side rendering and 25% faster component initialization.
Numeric redesigned its design process by moving away from Figma to a code-based design system where designers work directly in the browser with interactive React components. This shift enables backend engineers to ship design-compliant features, non-engineers to create prototypes, and automated checks to enforce consistency, resulting in faster shipping and higher design polish across the product.