I built the same thing I'd planned originally, so the point is moot. YAGNI does nothing to stop you from misunderstanding the problem. And in the case of my problem, the metadata was fresh anyway. Generating it from scratch would have the same migration cost, but all the original tooling existed so I wouldn't be building the feature from scratch.

If the point is "what if the whole concept was wrong?" then sure, you got me. But the point is that I _did_ follow a YAGNI mindset and paid a considerable cost. Even if I had built the wrong thing, that doesn't negate the fact that technical debt had accumulated and prevented me from doing the thing I actually needed to do.

> YAGNI does nothing to stop you from misunderstanding the problem.

A lot of times it does because you usually gain more information about your users and problem domains as time goes on. So if you build a feature when you need it a lot of times you understand the feature better than before hand.

But I think we're all in agreement that if you understand a domain very well, think there is a very high chance a feature will be required, and it's a good deal more expensive to build later than now than you should build it now.