It sounds ridiculous when I phrase it that way, but I see things that are that obviously incorrect all the time. A huge problem is that software engineering is so incredibly abstract, ill defined, and nebulous, that it's non trivial to even find out that you're building a deck at all, much less what the load capacity should be.
Software engineering is hard because there's no rules and no answers and it requires mutual understanding among groups to an extent that rivals the Tower of Babel