Two main type of individuals in creating a product:

* Product / Idea Person

* Executioner

These can be 1 person, 2 individuals, or more.

If you talk in a programmer's language, it's the front-end and the back-end. 

If you talk in a designer language, it's the designer (UI, UX, IXD, etc) and the coder.

If it's another kind of product like building a house, I dunno.

It's just not important you have these 2 kinds of individuals in a start-up team, it's important they sync. It's important their minds meet. It's important they can talk on the same language. It's important they can go down to the level of being intimate.

Having great minds for each of these roles will not matter if they cannot penetrate each other. Having a great egg and a great sperm are useless. You have to inject the sperm to the eggs to make something out of them. And, it's a plus if the meeting process is very good -- like blowing each other's minds during the f*ck -- because you will love the product more. And, if the outcome fails, you will still feel good to do it again and again and again.

(I got this thought from Eric Su's talk, when he said something to the effect that he and BJ (piclyf's lead developer) are soulmates -- they could marry each other.)

So before starting a start-up, make sure you can imagine yourself making babies with your partner.