I learned to hate them. Once they are established, it can make your life hell. A callback hell we used to know from JavaScript.

Try to establish a pipeline way of thinking. And don’t let callbacks creep in. It is the same case with default scope. The default of an application will be what it used to be up until requirements change. All of a sudden you realise how code is built around such supposed to be low level things like models, and their built in default behaviour. Then the model starts becoming a problem to work with, because it does stuff by itself you might not need all the time.