Netlify is moving their React UI component library to Tailwind CSS:
what started with organised PostCSS gradually grew to become a complex and entangled global CSS architecture with a lot of specificity and overrides. … the added tech debt it introduces makes it difficult to keep shipping fast without adding any regressions. Besides, as the number of frontend developers contributing to the codebase also grows, this kind of CSS architecture becomes even more difficult to work with.
To accomplish this, they set a deadline, divided the work across their front-end guild, and tracked their progress on GitHub. They added some internal tooling for visual-regression tests and to make building class lists easier, especially for conditional cases.