Middleware in Rails - FastRuby.io

Rails uses middleware called Rack that sits between web servers and application code, processing HTTP requests and responses before they reach controllers. Rack provides a simple interface that allows each middleware layer to receive, modify, and pass along request data through a stack system. Authentication gems like Devise and OmniAuth leverage this middleware architecture to handle user sessions and OAuth flows automatically. Understanding middleware helps developers debug issues, implement custom features like API rate limiting, and better control their application's request processing pipeline.