I despise the term higher level, probably because I'm a software engineer. High level in software engineering is used to describe the most big picture, abstracted detail view of a design. Deep dive or low level is getting into the nitty gritty. I understand that they mean "discussions at a higher knowledge floor" but just wanted to air my grievance.
as someone who studied both computer science and "higher level" math, i think that the use of "higher level" does kind of loosely match the computer science meaning. "higher level" math is all about abstracting away the details, to focus on the "big picture" of how things work. e.g., measure theory focuses on looking at integration from a very abstract perspective, and this abstract perspective lets you treat summation and Riemannian integration as "the same thing". you can draw a parallel to how in programming, a higher level perspective lets you treat various operating systems/pieces of hardware as "the same thing".
another example would be how abstract algebra lets you treat various algebraic structures as "the same thing", e.g. just about anything is a group, lots of things are modules, etc. and then there's category theory.
probably the biggest difference is that higher level math tends to be more challenging than lower level math, while lower level computer science tends to be more challenging than higher level computer science. (at least in my experience)
It's because low level in terms of software engineering is like the foundation of a building, while high level in terms of the skill required to do something is like the top of a podium.
I mean this is the same issue you see in music where some folks wanna "get low" while other folks wanna "get on up". The conflict between down and up is universal.
High level in software engineering is used to describe the most big picture, abstracted detail view of a design.
The same once happened to "basic" and "fundamental". Up to this day, if you want a textbook that will really teach you a topic, you have to get the "fundamentals of X" one, "advanced X" will only have a few concepts here or there.
That's how language evolves. It's often stupid, yeah, because people as a group can't help but act stupid. But it is what it is. If it becomes too confusing some day, we just have to craft a new word for high-level or low-level engineering.