We have a couple of blog posts digging into gpui, but here is one from just after rewriting and shipping gpui2: https://zed.dev/blog/gpui-ownership

We’ve slowly been building out gpui to be super ergonomic and fluid for us to build the kind of UI we need to.

As a designer that just picked up Rust last February it’s been really nice to have something that is so comfortable to work with without compromising our performance goals.