>>On the otherhand, I know I would resent the technical cofounder receiving an enormous financial benefit from developing a non-viable disaster from which the c

>>On the otherhand, I know I would resent the technical cofounder receiving an enormous financial benefit from developing a non-viable disaster from which the company needs to be rescued. If the technical cofounder created a working prototype that allowed the company to achieve certain milestones (e.g. paying customers, seed funding) then I'm not sure why you'd be resentful because it seems the (initial) job was accomplished. You rightly point out that you bring a valuable contribution to the table, but it seems you might (possibly) be underestimating how capable and determined the founders (and their investor network) will be able to source somebody else to rearchitect the platform. If you're one of the few luminaries in your niche, then feel free to start negotiating for a large compensation package that includes serious equity or favourable provisions. If on the other hand you feel that there could be others that could rearchitect on a "good enough" basis at a (potentially) lower compensation price point, then perhaps you might want to lower your expectations walking into the initial negotiation. Either way, it intuitively feels that your expected negative emotional resentment is not the right frame to start evaluating the possibilities around this opportunity.