How much you consider yourself an engineer is irrelevant in this case: you either are one because you have a degree from an engineering school (not a university!), or you don't (it's a civilian title in Switzerland's case at least, "Eng." similarly to "Dr.")
Calling yourself a "software engineer" in Switzerland (and according to wikipedia, in a slew of other countries [1]) if you have a university degree is technically illegal - although of course, seldom enforced.