alt Hacker News> something like Celery with all it's underlying infrastructure.
Unpopular opinion, but combining this with the other "no thanks" sentiments in this subthread is the right answer. Your app is so complicated you need async? Then it's complicated enough that you can benefit from infrastructure. I don't want to watch coworkers try to badly rebuild message queue or scheduling semantics in an application code base. Just use infrastructure that's made by people who know what they are doing. That was problematic in 2015, but in 2026 it's a bit of docker, and it's not just about web/microservices. Very easy for sufficiently complex apps to simply leverage a local sandbox of celery, redis, graphdb's and whatever. Stand-alone is overrated since we don't have to do it anymore.. app devs should get more comfortable working with ensembles like this so they have access to best-in-class solutions.
You don't like infrastructure AND have such a need for performance AND don't want threads or multiprocess? Consider using another language. Async is mostly a solution in search of a problem, and the enduring popularity of TFA goes to show this has been the right conclusion for ~10 years.
I said nothing about "stand-alone" services. I'm all about using the right solution to the problem. We run on Kubernetes and have access to message queues. But if all I want to do is make a couple of HTTP calls concurrently, I don't think I should have to manage a thread/process pool to do so, or lean on a message queue or redis based RPC mechanism. In an async context I can do this with a single line of code.
Every rich client-side experience in your browser is written using async code in Javascript or Typescript, as is every electron app. Every developer at my company is comfortable with this pattern, and frameworks like FastAPI make this a similarly smooth experience when using Python.
If async was a solution in search of a problem, it wouldn't have been stolen from C# and added to Rust, Python, Kotlin, etc. The engineering effort required to bring this solution to all these languages is immense, so I'm clearly not the only person seeing value in it.