Design Systems

A design system is one of the most efficient routes to accessible-by-default user interfaces (UI): an accessible button built once, tested once, reused everywhere. But it can also lock inaccessible patterns into hundreds of products at once. Government design systems like GOV.UK and the U.S. Web Design System are useful references: their components are publicly documented, tested, and used at a scale where small mistakes have large consequences.

The hard part is keeping intent and implementation consistent. A component documented as accessible is no help if it ships an inaccessible variant, allows props that kill focus styles, or doesn't document the keyboard and screen reader behaviour that consumers need to preserve. Accessibility has to be a property of the component itself, enforced by API design where possible.

Ship native HTML where possible. Test every component with a screen reader. Document keyboard and assistive-technology behaviour alongside the visual spec. Don't expose props that break accessibility. Treat regressions as bugs that block release.