While I generally agree with that, the problem is teams, mixes of skill levels, and future time constraints. There's no guarantee the person doing the second i

While I generally agree with that, the problem is teams, mixes of skill levels, and future time constraints. There's no guarantee the person doing the second implementation knows about the first one, realizes they can be pulled into a better abstraction, or has the time to do it. On the flipside, it's possible the other person (or the first person with more experience) comes up with something better than the first possible version of abstraction. So it ends up being a trade-off you have to decide on at the start, rather than a simple rule, based on team experience and how big (or small [0]) the abstraction actually us. [0] https://www.folklore.org/Negative_2000_Lines_Of_Code.html https://www.folklore.org/Negative_2000_Lines_Of_Code.html