We are in the midst of YC interviews right now and I had a few bits of advice for interviewees that I thought I’d publish while they are still top of mind (in no particular order):  

1. Don’t use buzzwords. Speak in plain language.

2. Have a conversation with us. Don’t deliver a prewritten “pitch.”

3. Sometimes we’ll want to see a demo, but most often we just want to talk about what you’re doing. If you rely on a demonstration to explain what you’re doing, that’s a bad sign. Being able to explain something in words shows you really understand it.

4. Relax (I know this is easier said than done). We want you to do well! And we are very expert by now at overlooking the little things that go wrong in interviews.

5. We love learning new things. And a good startup idea usually teaches you something when you encounter it. Don’t worry if the new things about your idea are things only someone in your field would care about. We like that. We’d rather have interesting details than boring generalizations.

6. We don’t have lots of time for pleasantries, unfortunately. We have a fixed amount of time and we want to spend it learning about you and your idea. So please don’t take it personally if we jump right into things.

7. There’s no one specific set type of interview. They can go in many different directions. So don’t worry if the interview doesn’t take the form you expected.

And here are Michael Seibel’s 10 pieces of advice for preparing for a YC interview.