I don't think any job where you're expected to do the same thing every day could possibly satisfy an ISTP. Unfortunately, that's kind of the nature of most jobs-- that you do the same thing every day.
Engineering is not necessarily like that. Obviously, what I work on is all loosely around the same type of thing (since it's a electronics company, obviously it's all somehow relating to them.), but I work on a wide variety of things, and that isn't just doing what people think of as "engineering". It also means working with/on the hardware to get it to do what I need it to for whatever I'm working on, making whatever software is involved to do that, etc...
The actual "engineering" portion, is small compared to all the work that you have to do to test the idea or whatever.
I love my job and i'm an ISXP. I'm an Implementation Specialist for an IT Company. I work in the field opening new hotels and train the front desk and managment at that property how to use my companies Property Management System. To me it keeps me entertained i'm always troubleshooting an issue, tweaking the server and whatnot. I'm getting better at SQL Plus but still learning. I'm new to the job so it's a challenge and the best part is every 4 days i'm somewhere new..or home kickin' it!
ESTJ (SJ Guardian) - Middle Management/Administrative. Not in control of the company's overall direction or broad-scope strategic planning, but excellent at delegating tasks to lower level employees and translating directives from upper management into tangible results, on schedule!
That was probably easy to find. I mean, only every single ESTJ description mentions administration skill. It's kind of annoying to be put in that box, on the one hand... on the other hand, it's true, for the most part.
ESTJs might be good with inventory, too (though they could piss off the INTPs).
p.s. Speaking of middle management, I'm reminded of Lumbergh, from Office Space: "So if you could be here around... niiine... that'd be greeeat."