In addition to the issues others have pointed out, I think there was a bit of a language and culture barrier. The author says, "We entered the room and facing u

In addition to the issues others have pointed out, I think there was a bit of a language and culture barrier. The author says, "We entered the room and facing us there were 3 young boys in their early twenties." I get the impression he felt insulted, but it's not like the interviewers can choose their age. The statement is also odd because I don't think any YC partners are that young. Maybe his estimate was thrown off by their casual attire and demeanor. The author was annoyed by interviewers asking questions answered in their application. That's a natural reaction, but there are good reasons for this practice. Maybe some of your answers have changed since you applied. Maybe the interviewers want to get an idea of how much thought you've put into these questions. Maybe they're not satisfied with some of the answers in the application, and want you to flesh them out in person. My point is: the interviewers aren't trying to annoy you or waste your time. They want to understand you and your idea. Responding to their questioning with annoyance won't help them. I found it very unusual that the author ignored the post-interview e-mail. Those e-mails typically contain tailored advice, or at least reasons why the partners passed. That information is extremely valuable. YC's reason for passing will probably be similar to many other potential investors. Even if you don't think it's a good reason, it's worth crafting a solid response to. One more thing: If you have a demo, show it as early as possible! A demo can obviate the need for many "What are you making?" questions, since it shows the answer. That leaves more time to discuss your product or idea, instead of trying to explain it to the interviewers. With that feedback out of the way: I wish Creo success and I'm glad they plan to apply again. Good luck!