On: I Am Sam Altman, President of Y Combinator. AMA

[sama]

Why don't you have a prototype? That'll be an important question.

That said, we make most of our money backing companies at the "initial concept" stage, so we'd love to hear from you.

[Gozu → sama]

We're working on a prototype but it takes time and having a full-time job limits our commitment and progress. It's good to know because being funded will literally help to be focused on this idea.