The ten questions
Q1
What are you building?
What they want: One sentence a stranger understands. No category jargon, no vision speech.
Trap: Spending 90 seconds on the problem before naming the product.
Q2
Who are your users?
What they want: A specific named person or role, ideally one you spoke to this week.
Trap: "Small businesses" or "developers". Too broad reads as no users.
Q3
How do you know they want it?
What they want: Behaviour, not opinions. Usage, retention, payment, waitlist conversion.
Trap: Quoting encouraging things people said in interviews.
Q4
What are your numbers?
What they want: Revenue, active users, growth rate — recited from memory, instantly.
Trap: Any hesitation. Not knowing your own numbers ends interviews.
Q5
Why you? Why this team?
What they want: Unfair insight or unfair speed. Something specific to your history.
Trap: Generic passion. Everyone is passionate.
Q6
How do you make money?
What they want: A concrete price and unit, even if it is provisional.
Trap: "We'll figure out monetisation later."
Q7
Who are your competitors, and why will you win?
What they want: Naming the real ones, including the incumbent everyone uses.
Trap: "No one is doing this." Partners hear: you have not looked.
Q8
What's the biggest risk?
What they want: The honest one, plus how you would find out fast.
Trap: A fake weakness dressed as a strength.
Q9
What have you shipped in the last month?
What they want: A list. Velocity is the single most legible founder signal.
Trap: Planning language instead of shipped things.
Q10
What happens if we don't fund you?
What they want: You keep going. Say it plainly.
Trap: Any answer implying YC is the plan.
How to prepare in a week
- Write one-line answers to all ten questions above. One line, not a paragraph.
- Know your numbers. Revenue, users, weekly growth, retention. No notes.
- Run timed mocks. Use a short conversation with real follow-up questions; avoid rehearsing the same script repeatedly.
- Cut every answer in half. Then cut again. Partners want density, not narrative.
- Practise stopping. Answer, then be silent. Over-talking is the most common failure mode.
Interview odds in context
An interview is a chance to discuss your company, not a reliable percentage chance of admission. We do not have a verified current interview-to-offer rate. For broader context, see our YC acceptance rate page and check the sources behind any historical figure. If you are still at the written stage, start with the YC application questions and the accepted application examples.
Common Y Combinator interview questions
How long is the YC interview?
Ten minutes. It is deliberately short and deliberately fast. Partners interrupt, cut you off mid-sentence, and jump topics. That is the format, not a sign it is going badly.
What questions does YC ask in the interview?
Almost always: what are you building, who uses it, how do you know they want it, what are your numbers, why you, how do you make money, and who are your competitors. Everything else branches off those.
How do I prepare for the YC interview?
Do timed mock interviews with a stopwatch. Practise giving a concise first answer, then listen for follow-up questions instead of memorising a script. Know your top-line numbers cold. Rehearse the one question you are most afraid of.
What is the YC interview acceptance rate?
There is no verified current interview-to-offer rate in the sources cited here. It varies by batch, so do not treat a commonly repeated percentage as your odds. Focus on explaining your actual progress and what you have learned from users.
Is the YC interview in person or on video?
Interviews are conducted over video. You will be on a call with two or three partners, and the whole thing is over in ten minutes.
When do you hear back after the YC interview?
Usually the same day, often within a few hours. Offers come by phone; rejections come by email with brief feedback.
What YC interview questions should I prepare for if I have no revenue?
Be ready to explain the problem, the people you have spoken to, what you have built and how they use it. Say plainly that revenue is zero. Separate paying customers, active users, pilots and waitlist sign-ups rather than presenting them as the same thing.
How do I answer “What are you building?” in a YC interview?
Name the customer and the job your product helps them do. For example: “We make scheduling software for dental clinics so patients can book cancelled appointments.” This is an invented example of a clear explanation, not an accepted YC answer.
How should I answer YC interview questions about competitors?
Name the alternatives customers actually use, including manual work or an established product. Explain one specific difference and the evidence that users care about it. Avoid claiming you have no competitors just because no product is identical.
What if I do not know an answer during my YC interview?
Say what you know, what you do not know and how you would find out. Do not invent a metric or customer claim. An honest gap is more useful than a confident but unsupported answer.