How do you make accessibility sustainable across a large organisation with many teams, instead of a one-off audit?

Treat accessibility as part of the platform and part of the definition of done. Here is how, in four parts.

Built in: design system components are accessible by default. They handle focus management, roles, labels and keyboard support. So most of the work is done once. Lint rules like jsx-a11y catch common mistakes in the editor. "a11y" is short for accessibility.

Automated checks: axe, an accessibility testing tool, runs in component tests and end-to-end tests in CI. It fails the build on violations. Automated tools catch only some of the issues. So they are a minimum level, not proof.

Manual checks:

• A short keyboard and screen reader checklist in the PR template, for UI changes.
• Regular audits of key flows with people who use assistive technology.

Ownership:

• A target standard: WCAG 2.2 AA.
• Accessibility champions in each team.
• Training.
• Accessibility bugs triaged with the same severity scale as other bugs.

Design reviews check contrast, focus order and target sizes before anyone writes code. This is called shifting left: catching problems earlier in the process.