We did. (OK, I was contracting which isn't a corporate job in the first place. But I gave up a lot of potential income to do YC.) I second those who are saying

We did. (OK, I was contracting which isn't a corporate job in the first place. But I gave up a lot of potential income to do YC.) I second those who are saying that simply filling out the application (and especially, making the video - boiling your startup down to 1 minute is HARD) will be really rewarding. I would recommend that you and your co-founders make a pact: if you get in to Y Combinator, you will do Y Combinator, full-time, 100% all the way. If anyone can't agree to that, then you shouldn't apply. Or maybe find a new co-founder.