YAGNI is very useful. But :- It's mostly useful in a situation where problems that YAGNI was trying to help with are happening. Namely, when people are tryin

YAGNI is very useful. But :- It's mostly useful in a situation where problems that YAGNI was trying to help with are happening. Namely, when people are trying to ask for anything that is possibly needed upfront because if you change your mind later it will cost a lot more to get it. For developers it was to try and get them to think vertically through software rather than horizontally and to stop designing large layers of goop instead of focusing on working software which you build out incrementally which means a HUGE focus on composable modular software. It's also not a justification by itself. Lisa: "Lets do X" Bart: "YAGNI" There needs to be a bunch of thought about things and YAGNIs purpose is really to just challenge what it is that is going to get built. Most of the criticism of YAGNI is mostly YAGNIing something that was actually needed, or using YAGNI to compromise a software design. But that's not a fault of YAGNI, that's either because you let YAGNI hold too much power over your decision making because you felt its pressure to stop you doing something, or you just weren't capable at decision making time to work out what you really needed. YAGNI is just a focusing tool to work out what you are going to need and it's as strong or as weak as the people making the decisions.