I never hear any production app with elixir in Berlin, some noise with clojure, but some people move from node.js to Golang. As for rails, people are happy.
Sometines I think is super cool to rant rails :)
As a ruby/js dev moving to Berlin in September, that's good to hear. I'm interested in talking to folks who might be more familiar with the scene there. If you know anyone who'd be good to reach out to, let me know!