This. Develop the logic and flow for all of the thing, make it big, code it simple and even redundant, but really basic and simple. That's your "proof of concep

This. Develop the logic and flow for all of the thing, make it big, code it simple and even redundant, but really basic and simple. That's your "proof of concept". Pass two is finding and factoring out all of the redundant stuff into functions and libraries, grouping like with like. It's like in relational database design - first you grab all the fields needed, then group them and normalize them.