It's solving and building, but most of all it's language. It's all language. Either telling the machine what to do or coordinating a group of people cohesively.

That's where engineering fits in. It's in the knowledge and information space, you make things like plans, arguments, decisions, documents.

That's not to say it all needs to be written down; someone can do the "engineering" of a small project all in their own head and then implement it themselves.

The engineering process itself is a form of knowledge work. A single person can do both tasks of course.

I actually read an interesting study, probably here, about software engineers. It turns out that for as much emphasis as we put on mathematics we actually tend to be better at language, and that even our penchant for maths is less in the way of calculation and more in the way of definition and expression (which is to say, making it the language numbers speak and learning it that way).

You mean communication, the transfer of ideas. Already hard between humans, machine language and operation is completely foreign.