[athenot]

> Node.js isn't particularly excellent at anything

That's not very kind. Yes it has its flaws but it's not bad at being a higher abstraction over async-everything, augmented with a huge module repository. Support for isomorphic javascript can come in handy for some applications.

I've never done Scala but my understanding of it is that it could be a good fit for modelling certain types of business logic while being able to take advantage of exiting java libs out there.

> Knowing more than one tool in the toolbox is a key skill, since there is no one-size-fits-all.

Yes, we agree here. That was the point I was making.

[pencilhappen]

Node is adequate at async, but not excellent. As I said in a sibling comment, things that are synchronous still, like GC, make it fall down at scale. Isomorphic JS isn't that useful in most real situations.

My point about Scala is that there doesn't seem to be a clear cut niche that it excels at. There are numerous other non-Java languages that run on the JVM that could be in the running, and they all get to take advantages of the whole Java ecosystem too.