"Twitter scale" wasn't so much a Ruby/Rails problem as it was an RDBMS (write-many + read-many = road to fail) and writing their own in-house message queue problem. Starling performed worse than just about everything else out there (and their Scala replacement Kestrel isn't much better).
One really insipid blog post and thousands of mindless followers later and the damage to Rails has been done.
That's not to say Rails doesn't/didn't have other issues -- it did. It's just telling that Twitter is the first example people reach for instead of anything else.
Agreed. I've been working mostly in Ruby since 2006, over hundreds or thousands of apps, depending on how you count, and I have only worked on 2 apps that actually had scaling problems with Ruby. The rest were 100% improperly designed or scaled databases.
Twitter is certainly of a scale that I would not be using Ruby on the primary load points. But even billion dollar companies don't often reach that scale.
at twitter’s scale, its not jus ruby, you would also have problems with php, python, node, and maybe even java. only language that will work well at that point are languages built for concurrencies such as scala, elixir, and go.
Or you break out your infrastructure into smaller components and move the more demanding/critical parts of your infrastructure to that other language and keep everything else you've built!
One really insipid blog post and thousands of mindless followers later and the damage to Rails has been done.
That's not to say Rails doesn't/didn't have other issues -- it did. It's just telling that Twitter is the first example people reach for instead of anything else.