Yes sorry that was an over-simplification due to ignorance - Ruby 1.9.3 and Python are both compiled to bytecode now, but still tend not to do as well in speed comparisons to the Java VM (which perhaps has just had more effort on optimisation). So in that sense it is like Java, but slower - for most people that really doesn't matter, but for twitter with this level of traffic, it probably would. You can of course run Ruby on the JVM now too, but I think that came too late for twitter.
What I found interesting from another twitter blog post linked from the article was that they are actually running on a modified version of Ruby 1.8.7 REE, not Ruby 1.9.x as you might expect, so that must really skew their comparisons![1] Anyway, there are a lot of variables in a huge system like twitter, so boiling it down to just a problem with Ruby performance seems pretty simplistic (as you'd expect from the register), and I seriously doubt they could have avoided this kind of rewrite and refactor of their entire stack in any language when hitting this sort of scale. To me it doesn't say much at all about Ruby as a language or whether it is suitable for websites.
> python is not interpreted,it is compiled in bytecode just like java.
Depending on the implementation, so is Ruby. The canonical MRI 1.9 compiles to bytecode and interprets it. But unlike python, it doesn't write the bytecode to disk. The loading of bytecodes has been disabled until a bytecode verifier is implemented.
