I agree that often no salary != founder. For instance, a recruiter, legal advice, or short term contractor might agree to a small equity share instead of a pay

I agree that often no salary != founder. For instance, a recruiter, legal advice, or short term contractor might agree to a small equity share instead of a payment. Without more information, we can't be sure about the current situation. But it sounds like there are only 2 other founders, no employees, and no product. I'm not sure if there is any funding or investment at this point either. Because the original poster would be the first technical employee, I'm going to guess there hasn't been much prototyping either. Considering that this guy would be the third in the company and would be the first guy with a technical background, I think it sounds like a no salary == founder situation.