There's a little big detail w/r/t java comparison: every company I've personally worked with who uses rails for their backend vs java moves WAY WAY WAY faster. So in terms of the "enterprise stack" dichotomy, there is a difference in kind between rails/java.
I get things done faster and more maintainably (for future me and other devs) when I do it in rails. Hopping into apps that rely on (request, response, next) always hits me with a learning curve every single time I come back to em, which gets worse as complexity rises. It could also be that I'm very bad at thinking in terms of pipes and need to practice that more.
I also find that in rails, there really aren't _that_ many ways to do things. And, in general, apps that age gracefully always figure out how to phrase their domain concepts through the smallest restful url's/resource mappings they need. There's a lot to be learned from the approach the smaller micro frameworks take, and you can get the best of both worlds in a lot of ways.
And there are some companies where you need to move fast while at the same time need to have high performance (100.000 req/s with 30-50 ms mean latency). In that case Java is the only option between Rails amd Java.
The gap between Scala + Play and Ruby + Sinatra (or cut down Rails) is not like it was in 2008. Ruby 2.5 is ~13x faster than Ruby 1.8. Now you're lucky to squeeze 3x the web throughput out of a Java/Scala service as opposed to CRuby and JRuby closes that gap further.
Can you point to me any performance site where Ruby 2.5 + Rails that backs your point? If you use JRuby than you are on the JVM already. In that case why Rails at all?
My own experience at ChartMogul with building production services in Ruby, Go and Rust is that the overall throughput of REST API type services increases a disappointing amount.
With JRuby you get to retain all the benefits of the Rails ecosystem. Most of the Go and Scala community is driven by much larger companies who do open source libraries but they don't really build frameworks to help developers build software quickly.
I get things done faster and more maintainably (for future me and other devs) when I do it in rails. Hopping into apps that rely on (request, response, next) always hits me with a learning curve every single time I come back to em, which gets worse as complexity rises. It could also be that I'm very bad at thinking in terms of pipes and need to practice that more.
I also find that in rails, there really aren't _that_ many ways to do things. And, in general, apps that age gracefully always figure out how to phrase their domain concepts through the smallest restful url's/resource mappings they need. There's a lot to be learned from the approach the smaller micro frameworks take, and you can get the best of both worlds in a lot of ways.