You wish! Bus factor risk is why you don’t do this. Having siloed knowledge is one of the first steps towards engineering, unless someone else code is proven bug free, you don’t usually rely on that. You just have someone to throw bug tickets at.

Very true, my brain is stuck in scaling out from small teams. In that world, you can't help but accept plenty of bus factor, and once you get to enough people making sure everyone understands each others' domains is a bit too much.

EDIT

*towards bad engineering, unless*