Have a browse through their engineering blog: https://blog.twitter.com/engineering/en_us https://blog.twitter.com/engineering/en_us It's largely focussed on th

Have a browse through their engineering blog: https://blog.twitter.com/engineering/en_us https://blog.twitter.com/engineering/en_us It's largely focussed on the event stream behind the core service and data analytics. There's maybe one entry on the main data store and one on search over the last few years.