Ask HN: Splitting profits between a programmer and a sysad/network engineer?

Hi guys!

Let's say my friend and I got a nice freelance job going that pays a lot. I did the software dev and he does the sysad and networking duties. How do we split the profits?

To make it a bit more complicated, what if we outsourced some of the tasks. How do we know how much to split?

Any help/comments/suggestions would be greatly appreciated. Thanks in advance for helping us out!