A SWE shouldn't even think of software as simple. "Layers upon layers, all interacting with each other, and all changing constantly" describes any software org. And I can't even imagine running a city.
To take the metaphor further, it's like this except the software is hosted on GitHub and open to public commits with limited moderation. It grows and changes on its own without anybody really knowing what's happening in total. (Here your metaphor needs no expansion)