It's weird to be talking about game rendering engines in a channel that is A) Compose (reactive framework) and B) Desktop (as in writing "traditional" desktop apps)

Is it? At the end of the day, reactive frameworks normally sit on top of a non-reactive UI layer, and that UI layer is typically what draws to the canvas. I’m possibly speaking ignorantly. Either way, asking if that layer exists in compose, or is exposed externally seems like a normal question. i.e. Flutter exposes it. I remember watching talks early on that coding in the RenderObject layer in Flutter is similar to coding something in Android or iOS using native View’s.

Well, game rendering engines target something a bit different - get thousands, millions, billions of highly textured, constantly changing pixels on the screen. Most desktop UIs (in the traditional definition of desktop, aka Office, AutoCAD, etc) do not need that.

I’ve been corrected in another thread. I assumed Compose was writing to a shadow dom that was then diffed and drawn to the UI. Clearly I need to read more about how Compose functions under the hood.