Comment by narnarpapadaddy

Appreciate the charitable interpretation. Both “complexity“ and “abstraction” take many different forms in software, and exceptions to the rule-of-thumb abound so it’s easy to come up with counter examples. Regardless, thinking in terms of complexity ratios has been a useful perspective for me. :)

IMO, a function _can_ be an interface in the broadest sense of that term. You’re just giving a name to some set of code you’d like to reuse or hide.