I'll qualify this with the fact that I've never done any embedded programming, but my feeling is, that relative to a GUI application, that things are still fair

I'll qualify this with the fact that I've never done any embedded programming, but my feeling is, that relative to a GUI application, that things are still fairly predictable. Unpredictability seems to arise mostly from interuptability. GUI applications have the ability to jump from a large bank of states to another large bank of states with almost endless permutations and maintain several, not one state simultaneously. At least in systems programming and I'd assume embedded programming (and like I said, I'm guessing -- I'd be interested in your take there) the chain of interruptability is much more structured and the logic flow inside of components is much more atomic.