You can apply this rule to the structure of your codebase/class: make a lot of small, focussed classes rather than one big class that does everything. This way

You can apply this rule to the structure of your codebase/class: make a lot of small, focussed classes rather than one big class that does everything. This way you can easily debug it, replace the logic of 1 class without breaking your whole application. One of the best advices for me was: your function must do one thing only, and do it good.