I should say that software complexity is different than normal engineering complexity; physical constraints are replaced with cognitive constraints on managing

I should say that software complexity is different than normal engineering complexity; physical constraints are replaced with cognitive constraints on managing abstractions. To address both: designing a modern microprocessor is very complex. I think certain software tools used to aid in this, e.g. a simulator to test designs, are very complex. These complexities are different: the former is based in science and the latter is based in logic. Even so, they intersect in the real world, but aren't equal. I think the latter has a much higher ceiling for difficulty, as complexity comes for free there.