I was offered three ways of being a participant: 1- To be a
shareholder. 2- To get paid with a fixed salary. 3- To be a
shareholder and get a fixed salary. From my point of view seems like
the third option to be more convenient. But I think I need a clearer
explanation from people who previously had to deal with this kind of
The only real way to ...
To answer this, one would need details about the startup including a hard look at the business plan and the size of the market. (And need to sign an NDA to see those.) If you don't know how to evaluate the potential business, you are "shooting blind".
Typically, a person who is in the role of "head of development" of the product will be a ...