Early days of Twitter were a lot of scaling issues due to the choice and implementation of RoR and they considered a lot of things, which got a lot of public attention. 13 years ago...
https://venturebeat.com/2008/05/01/twitter-to-jump-off-ruby-...
https://venturebeat.com/2008/05/01/twitter-to-jump-off-ruby-...
Shopify does probably have better engineering though. They have an amazing process of 2 code reviewers per PR, and one code reviewer is from another team. They write tests for everything and deploy continuously to production.