I concur with that advice, it seems that the startup founders are looking for a naive young guy to work for free before getting some funding. If you (OP) are re

I concur with that advice, it seems that the startup founders are looking for a naive young guy to work for free before getting some funding. If you (OP) are really interested in that position and trust the founders (I wouldn't, but I haven't met them in person, so who knows?), then you should become a co-founder and ask for significant amount of equity in the company (10% at least).