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

The single word that matters most I think to keep the company productive as it grows is alignment.

AirBnB spent 5 months interviewing their first employee, before they hired someone and in their first year, they only hired 2 people.

The startups that do well are the ones that are working all the time.

Execution gets divided into two key questions: 1) can you figure out what to do and 2) can you get it done.

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.

Before product/market fit, your only job that matters is to build a great product.