One thing that often disrupts momentum and really shouldn't is competitors.

The most common post YC failure case for the companies we fund, is they're incredibly focussed during YC on their company... and after they start doing a lot of other things. They advise companies, they go to conferences, whatever.

Experience matters for some roles and not others.

Don't let the company get distracted or excited about other things. A common mistake is that companies get excited by their own PR.

The second part of how to hire: try not to.

By the way, that's my number one piece of advice if you're going to join a startup: pick a rocket ship.

Developing a personal connection with anyone you're trying to do a big deal with is really important.