Investors will sort of like write the check and then, despite a lot of promises, don't usually do that much; sometimes they do.

You don't get to make their decisions but you do get to choose the decision makers.

Here's a good rule of thumb: don't worry about a competitor at all, until they're actually beating you with a real shipped product.

If you compromise in the first five, ten hires it might kill the company.

Stay focused and don't try to do too many things at once. Care about execution quality.

In general though, if you look at the track record of pivots, they don't become big companies.

Many of the best YC companies have had phenomenally small number of employees for their first year, sometimes none besides the founders.