No growth hack, brilliant marketing idea, or sales team can save you long term if you don't have a sufficiently good product.

No matter what you choose, build stuff and be around smart people.

It's easy to move fast or be obsessed with quality, but the trick is you have to do both at a startup.

You want an idea that not many other people are working on, and it's okay if it doesn't sound big at first.

... We probably funded a rate of something like one out of ten solo teams.

One of the keys to focus, and why I said cofounders that aren't friends really struggle, is that you can't be focused without good communication.

In YC's case, the number one cause of early death for startups is cofounder blowups.