You really want to know your cofounders for a while, ideally years.

What you want to do is innovate on your product and your business model, management structure is not where I would try and innovate.

In YC experience, 2 or 3 co-founders seems to be about perfect.

Most founders have not managed people before, and they certainly haven't managed managers.

Move fast. Speed is one of your main advantages over large companies.

You have to let your team get all the credit for all the good stuff that happens, and you take responsibility for the bad stuff.

Great execution is at least 10 times more important and a 100 times harder than a good idea.