To the extent that there is a real distinction between "Systems Programming" and "Whatever is not Systems Programming" and to the extent that this distinction matters, I tend to align with the take espoused in the Systems Programming[1] Wikipedia page:
The primary distinguishing characteristic of systems programming when compared to application programming is that application programming aims to produce software which provides services to the user directly (e.g. word processor), whereas systems programming aims to produce software and software platforms which provide services to other software, are performance constrained, or both (e.g. operating systems, computational science applications, game engines, industrial automation, and software as a service applications).
That is to say, the distinction I consider to be somewhat meaningful is between "Systems Programming" and "Application Programming", and I think this expresses the most salient aspect of the difference:
application programming aims to produce software which provides services to the user directly (e.g. word processor), whereas systems programming aims to produce software and software platforms which provide services to other software
But is all of this terribly important? Meh. I am not convinced that it is a terribly important distinction in most day to day contexts. And that's at least partly because the lines do seem to be a bit hand-wavy, subjective, and fuzzy.
[1]: https://en.wikipedia.org/wiki/Systems_programming
The primary distinguishing characteristic of systems programming when compared to application programming is that application programming aims to produce software which provides services to the user directly (e.g. word processor), whereas systems programming aims to produce software and software platforms which provide services to other software, are performance constrained, or both (e.g. operating systems, computational science applications, game engines, industrial automation, and software as a service applications).
That is to say, the distinction I consider to be somewhat meaningful is between "Systems Programming" and "Application Programming", and I think this expresses the most salient aspect of the difference:
application programming aims to produce software which provides services to the user directly (e.g. word processor), whereas systems programming aims to produce software and software platforms which provide services to other software
But is all of this terribly important? Meh. I am not convinced that it is a terribly important distinction in most day to day contexts. And that's at least partly because the lines do seem to be a bit hand-wavy, subjective, and fuzzy.
[1]: https://en.wikipedia.org/wiki/Systems_programming