SRP and my Head
Many years ago, whilst working at an Investment Bank with a number of ThoughtWorks colleagues, we were thinking about how big objects should be. Obviously as developers we were thinking in terms of the Single Responsibility Principle, Open-Closed Principle and Separation of Concerns.
I came up with a simple heuristic. Simply stated, an object should be no bigger than the
size of my head when pressed up against the monitor – basically a screenful of code. Now, I have a fairly big head (but thats ok, cos there ain’t much inside it) so your mileage may vary.