This is not the first time I'm hearing this... So many java developers have been spreading this propaganda that Ruby on Rails applications are slow which is non-sense because the only thing that makes an application slow is the nut coding it.
I've coded in C++, MFC, java and .net before I started coding in Ruby and I've seen many obvious benefits that Ruby and Ruby on Rails gives to the coder and the code -
2. A long list of plugins - Gems we call them. Just think of a use case and there's a already a gem which does that.
3. Speed of development - You start seeing considerable progress within half an hour.
4. Agility - Ruby on Rails has agility at its core given the features of data migrations and built-in unit test suite.
I don't have the stats around it, but I haven't seen any developer community more paranoid about TDD and BDD than ruby community which is the foundation of Agile development and quality code.
Heard that Ruby is slower than Java?
1. There is JRuby - the java implementation of Ruby - it bridges the gap.
2. Did you know that most of the heavy lifting is done in C? And that ruby makes it very easy to wrap in your native extensions as Ruby gems?
So, the next time your java engineers tell you that Ruby / Ruby on Rails is for toy apps. Well, say wtf!