It’s so annoying that right now the state of the art is essentially “just write all of your code as async because even sync callers could just spin up a one-off event loop in the worst case” in most languages.

The only language I know that navigates this issue well is Purescript, because you can write code that targets Eff (sync effects) or Aff (async effects) and at call time decide.

Structured concurrency is wonderful, but my impression is we’re doing all this syntactic work not to get structured concurrency, but mostly to have, like, multiple top-level request handlers in our server. Embarassingly parallel work!