It's difficult to give feedback without knowing what the product is. That said, the tradeoff most startup developers have to deal with is how to balance qualit

It's difficult to give feedback without knowing what the product is. That said, the tradeoff most startup developers have to deal with is how to balance quality vs time. At every stage of funding, this shifts more and more towards stability being important, but until you have users, you really just need to get the very basics working okay enough. Not all developers are good at accepting this approach. I even know of good developers that are not good at this approach, because it sometimes requires prioritizing product and instantaneous business needs over software engineering principles. However, it's really the best approach because most code you write today won't be there in 6 months or more as your understanding of the user and their problem(s) evolves. It is not an insult to your co-founder, if he's choosing not to work under this style. Perhaps considering contracting out building the prototype or learning to code yourself.