Much of software is a trade. But above a certain level, it is engineering.

For example, in my discussions with electricians, they understand very well how to wire up a house. But they don't actually know very much about electricity. For example, they had no idea what I was talking about when I objected them running the phone lines through the same holes as the high voltage. I said that due to inductive coupling, the phone lines would acquire a 60 Hz hum. The phone lines had to be run at 90 degrees to the high voltage wires.

They had no idea what inductive coupling was, whereas that's freshman electronics material.

I wound up removing all the phone lines and rewiring them myself. No hum!