Well, we all have to pay the bills somehow heizusan, small as your business may be right now, but I think an engineer is a definite ENTJ job, Te applying creative Ni in some interesting way especially with computer software. ENTJ's just gravitate towards leading and conquering other businesses though, but as a profession, engineering definitely applies to you. The inventive visionary ENTP's I personally consider thee engineering personality, as they're always engineering some big idea, moreso than any other type.
As for me, I'm a Mechanical Tech 3D draftsman that works WAY too many hours in front of Autodesk Inventor doing design work. Not that strange for an INFJ as IN likes design, which I just finished doing at work moments ago. We all need to pay the bills, and there aren't many jobs, at least good paying jobs nowadays in pure INFJ professions like counselling, writing, and humanitarian work, unless you're either a glutton for punishment and poverty or a savant, or do those things after work. It's often a lot of waiting before we get the job that applies to our personality. I'd prefer doing the profession I set out to do, Sustainable Community Planning, which to me would be meaningful and apply to my skill set, but there's no work if you don't already have work (experience required to get experience repeating ad infinitum), or have an in. My personality doesn't gravitate towards the specificity required to do my current job at all, as I'm a big picture person, and neither is it meaningful to me as I really don't take my work home with me as I did as a director of a therapeutic group home, which has been a great change of pace actually.