[StreamBright]

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.

[jashmatthews]

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.

[StreamBright]

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?

[jashmatthews]

In terms of pure Ruby performance, there's a semi-official non-trivial benchmark called optcarrot. Ruby 2.4 is 14.3x faster than Ruby 1.8.7 here: https://github.com/mame/optcarrot/blob/master/doc/benchmark....

Rails performance relative to JVM+Scala+Play is tricky to measure but the closest thing to a decent benchmark I know of is this: https://www.techempower.com/benchmarks/#section=data-r16&hw=...

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.