This is not in any respect limited to NodeJS. If you want to do a 500ms computation, you don’t want to do it synchronously in your network thread. It doesn’t make much difference whether it’s C, Rust, NodeJS, Go, etc. (CGI is different: everything is off the network thread.)
But this doesn’t mean you should outsource computations to a third party remote system. You can have a local (same physical hardware or same data center) off-thread service (or just thread pool) to do this kind of work with much nicer properties.
But this doesn’t mean you should outsource computations to a third party remote system. You can have a local (same physical hardware or same data center) off-thread service (or just thread pool) to do this kind of work with much nicer properties.