Give the Page a Skeleton
Decide what you would build from the brief alone. Everything below it is available, but the exercise stops working if you open it first.
A dashboard page is a tree of nested divs with class names like wrapper, content-area and left-col. Restructure it so the document has a real outline.
Adding role="main", role="navigation" and role="banner" to the existing divs and stopping there, because the landmark list is now correct in an audit tool. It is a real improvement and it leaves the second half undone: the heading outline is still driven by font size, so the page announces one region called "main" containing eleven h3s and no hierarchy. Landmarks help a user find the region; headings are how they move inside it. Fixing only the half a tool can check is how a page passes an audit and stays unusable.