I'm struggling to find out how it actually updates the DOM. The way that re-rendering happens is clear but it looks like the top-level function just returns a JSX.Element. There is no explanation how this is efficiently rendered.

Also how are mid-level invalidations handled? For example if I update a list to remove one element do the other elements get re-rendered or are they cached?

It might be because I am browsing the docs in mobile but I find them hard to navigate.