Http4s VS Vert.x

There are functional frameworks: https://http4s.org/

If you look at the example it is listed as an import but there is no explicit reference to it. And if you were just doing basic synchronous responses then that would be the only time you would see it.

If you want something more powerful, pure-functional and you need to do complex, concurrency-heavy operations, have a look at http4s: https://http4s.org/

I don't think this is toxic but still, it doesn't sit well with me: https://github.com/http4s/http4s/issues/4718

http4s

Here is a possible sketch with the functional http4s library. In http4s, both Http clients and servers are modelled as functions from Http requests to an Http response generated from an IO action. This would be like a function Request => IO[Response], which in http4s is called an HttpApp.

Http4s: https://http4s.org/

Have you checked http4s? I'm using it as a lightweight HTTP server with routing, etc. It might be not your cup of tea, if you don't use pure functional programming, etc, though.

[3] - https://vertx.io/

Another option that I would strongly consider is Vert.x. It allows you to mix/match languages and could be a simple and risk-free way to introduce FP concepts into an application.

I'm not sure about WebFlux, _specifically_, but yes it's different. I use VertX which has its own coroutine compatibility module, but essentially with reactive, you call database and get back some kind of "Future" object which then you have to use a callback with:

That being said, between the two you mentioned, spring is probably the more popular framework because of the magic annotation processing it provides if you're into that. Otherwise vertx seems like a good framework if you want something light, not sure which large projects are using it out there though short of looking at their site.

Something like Vert.x would be much close to node.js (it's inspired by it!) and it's pretty easy to use. I would also at least read about the following frameworks before deciding on which one to try a bit more:

Because the developers of Quarkus also worked on Vert.x, the former also offers a plugin that integrates the latter. Vert.x is full reactive and provides the concept of routes. With Quarkus, you can annotate methods to mark them as routes. One can migrate the above code to routes:

Backend newb, here. I have a dumb question - can someone give me a summary, or blog post to a summary, of the pros /cons of async versus threads?

One thing I have been using as a way of understanding hi-perf backends is analyzing why the vert.x framework [1] (and its underlying server, netty) does so well on benchmarks [2], but as newb, I do not think I would get a lot form that exercise without a little hand holding.

[1] https://vertx.io/

[2] Ad of today, #28 on tech empower benchmarks - https://www.techempower.com/benchmarks/

Came here to say this. Vert.x was inspired by Node+Express. It was even originally named NodeX.

Vert.x

Check out ES4X. It's JS and TS bindings for GraalJS for Vert.x. Vert.x is the basis for Quarkus, so this is definitely possible.