Around 2010 I really enjoyed working with JRuby. At that time dynamic languages weren't really a thing but I was able to convince my boss to try it in a project

Around 2010 I really enjoyed working with JRuby. At that time dynamic languages weren't really a thing but I was able to convince my boss to try it in a project because of Java library compatibility. So I used it for a Swing GUI application doing data processing combined with R, Postgres and Processing. It was really fun to write it. (Apart from that I also used in on Google App Engine) I never had the impression it was slower or less responsive than any other language, however startup times were quite slow. But I think that was due to the JVM. The way Ruby developed - into the language of Rails - I don't see myself writing anything CPU bound with it though. That said, I wish the article would just include numbers without the startup times. I also remember people claiming back at that time JRuby would be much faster than MRI.