Since you think the UI scene is maturing: Where do I find 1. design docs and 2. debugging infra docs (Validation, Testing, Stepping, Logging, Tracing, Recording, Scheduling, Reversal Computing as typical ones) and/or how to apply them ?

scheduling ??? what's that ? scheduling UI events ? Reversal computing ? What's that ? You meant reversible computing ?

Scheduling means to generate enumerations/combinations of possible ui events. If interleaving events are possible and to what degree, then providing a notion of that and/or at least documentation would be helpful.

Yeah, although I would define "reversible computing" as how to deterministically undo some computation(s)/effect(s) etc without recording the control-flow and I do not like the notation of "time-reversibility", because distinguishing between "reversible computing with known timings" and "reversible computing with unknown timings" becomes very confusing. So I'd phrase it somewhat differently, but did not come up with better naming yet. Context: https://en.wikipedia.org/wiki/Reversible_computing and https://en.wikipedia.org/wiki/Time_reversibility.

GPUI has a mature scheduling story, letting you “block” the main thread on spawned tasks with async/await. It also comes with a deterministic random test scheduler for driving out timing bugs.

Thanks. Sounds like a good developer experience attempt.