Have you ever tried JRuby? No GIL, true concurrency, all threads map to Jave threads. The speed delta is dramatic too.
Your app distributes as a war file to any j2ee server as well.
Yes, I once attended a JRuby workshop run by Charles Nutter at RubyConfAU. I was very impressed but at the time it was quite difficult to migrate existing apps. Maybe that's not the case any more?
I have always started with it. I fully expect it to be at least a bit of a pain to migrate any complex app.
If you commit to JVM world, then JRuby is a very rare choice, compared to excellent Kotlin, reasonably established Groovy and Scala or good-enough Java 8.
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