[ptero]

"Systems Engineer" seems to be an overloaded term. In the area I work in (applied R&D, East coast) the role is a mix of the software architect and QA, but encompassing both hardware and software.

Some science background (whichever science is relevant to the project) but mostly a lot of experience in general engineering practices (what generally works, how things break, what is sufficient to test to feel good that a unit will still work when moved from point A to point B, etc.). Many have software skills, but some do not. It is generally a high level role so not all projects have one even part time, but those that do tend to have it scoped roughly the same.

Projects that deal with field work / tests, especially bringing stuff to faraway / hard to get to places tend to value systems engineers (defined as above) highly and almost always have one at least part time. Just my experience.

[kingkongjaffa]

Again systems engineer can have more meanings still, when I hear systems engineering I think of interaction specification of mechanical / electrical systems particularly in automotive, rail, and aerospace.

managing actual physical systems, not software, although the skills are similar besides domain specific knowledge.

[amyjess]

I've also heard "Systems Engineer" used as a synonym for "Sales Engineer". That term is too overloaded to be useful.