[hoppi]

I'm in a startup with my brother. I would say it depends on the type of relationship you have with your brother, we can resolve various issues easily and quickly.

We think alike most of the time and if not, we know how to resolve it due to living with each other for a long time. That being said, we do have different roles and only certain parts of the startup are worked on together (frontend app etc..).

Clear and concise responsibilities are what is going to help the most. If you are competitive, you are usually the most competitive with your own blood, which can get messy if you fight over the same thing.