They still fail to understand that using Unicorn doesn't magically fix this issue. Like, at all. It simply means that the dunk gets tied up when n+1 requests (n is number of unicorn workers) get randomly routed to it instead of just 1. It's in no way comparable to a node.js server that handles thousands of concurrent requests asynchronously. They're simply two different designs, and Ruby's traditional design is fundamentally incompatible with Heroku's router.