Something I've only recently started to grasp is that good code isn't about taking abstraction and extensibility to the very maximum, it's about picking the rig

Something I've only recently started to grasp is that good code isn't about taking abstraction and extensibility to the very maximum, it's about picking the right amount of abstraction to fit the amount of change the code will likely face in its lifetime. Abstraction isn't without its own cost. Unfortunately, all of these design decisions - even the meta-decisions like degree of abstraction - are relative to the project and many of them have to be made at the outset, where you're only guessing what the future will bring.