Rails Concern is a good feature, don't make it evil . John McDowall has written an excellent article about how we are misusing rails concern. Rails concern are not meant to make your fat model skinny, its meant for making your life easy when you want to include, extend and use included callback ( all the same time) in a module . `Skinny Controller and Fat Model` is not enough for writing quality code. Fat Model is pain for maintenance and enhancement. Its nightmare for new developer on the project. We use Code climate to keep a check on code smell. Code climate complains when your model start becoming fat and simple option to shut code climate is to pull out some methods related to same logic and dump in a module or concern and code climate gives you green signal. Even though code climate says your code quality improved but in reality you have just deteriorated your code quality. According to code climate team `Pulling out methods from model to some module is not r