Accessibility isn't just a "Nice to have." For enterprise and government apps, it is a Legal Requirement. Beyond that, it is simply good engineering. An accessible app works better for everyone, including users on mobile or with slow connections.
The most important rule of a11y: **Use the right tag for the job**. Don't use a <div> with an onClick when you should use a <button>. Screen readers understand semantic tags automatically, but they struggle with non-semantic "Div-soup."
When standard HTML isn't enough (e.g., a complex custom slider), use **ARIA (Accessible Rich Internet Applications)**. aria-label, aria-live, and role="tablist" bridge the gap between custom JS components and screen readers.
Q: "How do you test for accessibility in your CI/CD pipeline?"
Architect Answer: "I use a multi-layered approach. 1) **ESLint-plugin-jsx-a11y** to catch errors during coding. 2) **Axe-core** integrated into Playwright/Cypress tests to scan for WCAG violations automatically correctly. 3) **Manual testing** with a screen reader (like VoiceOver or NVDA) and keyboard navigation. Automated tools only catch about 40% of issues; manual verification is non-negotiable."