Ruby is fine until your large application starts to include more and more dependencies. There is no coherent API across, every library has it's own mini DSL and the mess starts to build up. Then it comes method_missing, monkey patching and strings and dictionaries passing in all the places. True horror. All Ruby's readability dissapears. Small apps look beautiful, but large ones quickly become a mess. On top of that resource utilization is atrocious. But there are places where Ruby shines like RSpec, Rails, pry in runtime (I miss that one).