Programs nobody fully understands

I was reading about "emergent intelligence" the other day, which says no single member of a super-organism really knows what's going on in the whole.

Ants can work out as a group how to get a T-shaped log through 2 slits, when no ant could do it alone. Companies are similar. No individual really holds or sets the beliefs of the company as a whole. It's like a different beast entirely.

I'm seeing programs become more like that. They're so large and complicated that no one understands all of it, and yet they still work just fine.