That can be exteremly hard, if you're not writing code. Not all the roles and responsibilities directly translate to the world of private industry. For example a Systems Engineer in defense is loosely a product manager/ architect. However, it's impossible to get show all the responsibilities translate. Try explaining that to a recruiter... It tried for months.
I was in that boat for ~2 years (got out of it a little over a month ago). My problem was reduced in some respects, while amplified in others, because on my program systems engineers were developing signal processing algorithms[0] and implementing them in real-time signal processing software, in C. This caused all sorts of partial mismatches and misunderstandings, but ultimately the software piece got me out of there.
[edit] I would like to add that not being able to discuss what I did in meaningful detail was the most serious hindrance to my job search.
[0] This bit caused its own problems with a few companies, who saw "algorithms" and thought something else.
Yea, I'm pretty much a pure systems engineer. I'm working on teaching my self some code but it's not going to get me out of there. It's rough... I'm close though. Hopefully in a few weeks life will change.
Seriously. Try explaining PfM, UML, DoDAF or FEAF, to a recruiter. Or Troux, Primavera, System Architect, or DOORS. Or why ISSEP/ISSAP can be critical.
All while the recruiter is trying to do their job asking "Do you know C hashtag?" ... LOLWUT.
