So many people think accessibility is “one and done” but it is anything but that. Every time you make a change to the code, the accessibility has to be reviewed for that area. Every time you make a change to the content, that has to be reviewed as well. The same as true for physical accessibility. Spaces that have been lived in may have new accessibility issues when people move around furniture, for example. Accessibility is a program, not a project.
Alt: There are two categories of website accessibility-infrastructure and content.
Both have to remain accessible for the experience to be accessible.