[ksec]

>Nor did i know that twitter jumped out of rails before ruby got performant. Which means the argument that twitter outgrew rails isn't so correct anymore.

Twitter, even back in those days would have still outgrown today's Rails. It was Ruby that has gotten a lot faster. Not necessarily Rails.

[jashmatthews]

From what I understand, the biggest issue was their product required fast fan out messaging. Tumblr, for example, is still huge but can get away with 1000 lines of PHP for their feed: https://news.ycombinator.com/item?id=17154403