If you haven't read Netflix's Node.js in Flames blog post you should. It is a great deep dive into debugging a node performance problem. The post includes useful tips that can help you solve similar problems.

That said...

My feedback from the perspective of a framework developer is quite different. I found the tone and attitude towards express.js to be concerning and somewhat offensive. Here was a developer blaming the framework he chose for poor architecture when they never bothered to actually learn how the framework works in the first place. Everything that followed originated from this basic lack of understanding.

Express uses a very simple router logic which is at the core of how express works, so let’s examine that first (my knowledge of express is somewhat dated but I think the principle is still the same). Express keeps a hash of the various HTTP methods (GET, POST, etc.) and for each method, an array of middlewares. Each middleware is ju