[oorza]

That's why I like to tell people to always remember to stay MOIST - the Most Optimal is Implicitly the Simplest Thing.

When you add complexity to DRY out your code, you're adding a readability regression. DRY matters in very few context beyond readability, and simplicity and low cognitive load need to be in charge. Everything else you do code-style wise should be in service of those two things.

[HeavyStorm]

DRY has nothing to do with readability. The fact that it might help with it is purely coincidental.

DRY is about maintainability - if you repeat rules (behavior) around the system and someone comes along and changes it, how can you be sure it affected all the system coherently?

I've seen this in practice: we get a demand from the PO, a more recent hire goes to make the change, the use case of interest to the PO gets accepted. A week later we have a bug on production because a different code path is still relying on the old rule.

[oorza]

Maintainability and readability are two sides to the same coin. It's not exactly rocket science to cook up an example situation where making a change in one place is less maintainable than making it in two, because of overly DRY, overly abstracted nonsense leading to a _single_ place to change that's so far removed from where you'd expect it to be that it takes much longer and is much more wrought with risk than just having to do it twice.

Doing something twice is not an anathema, that's my point, not when doing it twice is a cognitively easier and practically faster task.

In almost every case, bugs are the result of human error, and keeping cognitive load as low as possible reduces the likelihood of human error in all cases. As DRY as possible is very rarely the lowest cognitive load possible.