Odd they didn't mention performance improvements in the blog post. From my understanding, there have been some massive gains (of which, some commits date back to early '15!) One of them which has been killing me, is that model schemas were not preloaded on app boot, which led to the first few dozen requests (depending on how many workers you have on Puma) perform 100+ sql queries and add over 1s to response times. Not only were they not preloaded, but they were not cached across ActiveRecord::Base.connection's

Good work rails team!