For example, as a TypeScript / React guy who likes MobX, I have used most of the API surface of those libraries at least once, so combined with type hints both

For example, as a TypeScript / React guy who likes MobX, I have used most of the API surface of those libraries at least once, so combined with type hints both inline & thru option-click in my editor I virtually never search on those layers. More when I'm trying to use some new backend library.