This seems really interesting, I would say I&#x27;m a bit concerned of the complexity it may add to JS when most developers are fairly familiar with the single-threaded model (or at least don&#x27;t need to think about it).<p>Where is concurrency beneficial? Are there other languages that are sometimes concurrent, and sometimes not?<p>Will a JS developer who is jumping between front-end and back-end get confused by the two paradigms?