Application Development
Section 508 is an engineering discipline, not a legal afterthought
Treating accessibility as a compliance bolt-on is how programs end up with audits at the end. We start every project with the audit assumed.
The cheapest accessibility work is the work you do during the first sprint. The most expensive is the work you do six weeks before launch when the Section 508 audit comes back red.
Accessibility tooling has improved enough that there is no longer a good excuse for the second pattern. axe-core in CI catches the obvious failures. Component libraries with proper ARIA semantics catch most of the structural failures. A screen-reader review on each major workflow catches the rest.
What does not catch up easily is a codebase that was not designed with semantic HTML in mind. If your component library wraps everything in nested div elements with click handlers, you can pass a Section 508 audit by retrofitting accessibility hooks — but the cost of doing so will be measured in months. We start every project with semantic markup as the baseline.