Go is kind of special, as it is new relatively and the initial implementation of every feature is usually the most basic possible. Thus, every new version there is space for a lot of improvements. What I mean: the garbage collector is/was for all intents and purposes Dijkstra's late 70s ('78) tricolor algorithm.

They eliminated re-scanning of the stack on Go 1.7 by adding a hybrid write barrier which is 90's work (found the proposal: https://github.com/golang/proposal/blob/master/design/17503-...). So Go is by no means state-of-the-art performance wise. That is not bad and has its benefits, one of them being that you can improve with every release.

> So Go is by no means state-of-the-art performance wise.

Yet Go is blazingly fast compared to most other languages that are widely used for web server development (except, maybe, Java).

Well, that's a heavily caveated statement.

It seems, given the end of Moore's "Law", as well as environmental concerns, that language efficiency will get more attention. It'll be interesting to see if languages like Swift, Rust, and Julia can gain traction for web development.

I wonder how uptake has been for IBM Kitura so far...

Same for us for Go. The releases have never caused any trouble and the performance improvements are nice to have. For us it’s just changing one base containers version.

That being said we still use mostly Python 2 for our Python services.

If those Python services are going to last beyond 2020 and there's much risk of attackers probing for security vulnerabilities, I suggest you plan a transition to Python 3 during the remaining ~2-year support lifespan of Python 2.

It's a lot easier of a transition than it used to be. Any other support replacement language would of course also work to keep you secure, but honestly might be more transition work.

If you're a low-value target running unimportant stuff on an airgapped machine, this might not matter.