What Happens At Y Combinator
(We realized recently that a lot of people don’t understand very well what YC does, so I wrote something explaining that in detail. Since YC has been shaped by the needs of hundreds of early stage startups, this should be interesting not just to potential applicants but to anyone curious about startups, because a portrait of YC is in some ways the complement of a portrait of the average startup.)
Y Combinator runs two three-month funding cycles a year, one from January through March and one from June through August. We ask the founders of each startup we fund to move to the Bay Area for the duration of their cycle, during which we work intensively with them to get the company into the best shape possible. Each cycle culminates in an event called Demo Day, at which the startups present to an audience that now includes most of the world’s top startup investors.
During each cycle we host a dinner once a week at Y Combinator and invite some eminent person from the startup world to speak. It’s a bit misleading to call these events “dinners” though, because they last half a day.
People start to show up for dinners around 6 pm. We encourage founders to treat each dinner as a mini Demo Day and bring laptops or mobile devices to show each other and us what they’ve built that week. We’ve found these weekly deadlines tend to push people to finish things in order to show them off.
The time before dinner is a chance for founders to talk to one another and to us in an unstructured way. Dinner itself happens around 7:15. Everyone eats together at long white tables designed by our architect Kate Courteau. The general atmos is like a modernist version of an Oxford college dining hall, but without a high table. 
The speaker usually shows up before 7 and talks informally with the founders before dinner. The actual talk
happens over dessert. Most speakers are successful startup founders, and the talks are usually about the inside story of what happened in their startup(s). Talks are strictly off the record to encourage candor, because the inside story of most startups is more colorful than the one presented later to the public. Because YC has been around so long and we have personal relationships with most of the speakers, they trust that what they say won’t get out and tell us a lot of medium-secret stuff.
I didn’t consciously realize how much speakers at more public events censored themselves till I was able to compare the same people speaking off the record at YC dinners and on the record at Startup School. YC dinner talks are much more useful, because the details people omit in more public talks tend to be the most interesting parts of their stories. About half the interesting things I know about famous startups, I learned at YC dinners.
One founder wrote:
Most of the practical advice is redundant, but there’s value in it even as such – if you hear the same things over and over again from different angles, especially from prominent people, it tends to sink in more. The stories tend to be galvanizing though, especially hearing about the screw ups. That’s the actual beauty in the off-the-record-ness: you hear just how screwed up most of these successful startups were on the way up.
It’s a shame the only record of all the YC talks over the years is in the memories and notes of founders who heard them. It seems inefficient that only the founders in that specific batch and a handful of alumni guests get to hear each talk.