> If you have to poll then it's not asynchronous.

Says who?

Maybe not "streaming". Maybe not "real time". But certainly asynchronous.

Yes, we have webhooks, and a grand total of 1 of our customers uses them. Setting up an HTTP server just to receive a webhook is a lot to ask.

Long poll lets the polling be efficient.

All push models are poll models down an abstraction layer.

And all computations can be modeled as Universal Turing Machines at some level. That doesn't mean it's the most useful level at which to analyze the semantics of what you are trying to accomplish.

Sure but saying something isn't asynchronous because its polling is flat wrong.