I faced recently scaling/refactoring problems due to way too large models and some kind of callback-hell baked in. instead of just "drag-n-drop" model code to c

I faced recently scaling/refactoring problems due to way too large models and some kind of callback-hell baked in. instead of just "drag-n-drop" model code to concerns/mixins/..., have a look at https://github.com/cypriss/mutations https://github.com/cypriss/mutations to extract business logic in a clear way. This was just a life-saver for my team, this should be preferred over "stuff any logic in your models", at least from my point of view.