What a strong answer does: One line, then anchor it to something they already know. This is the question that sets up the other nine minutes.
DropboxS07Drew Houston · Written YC application
“Dropbox synchronizes files across your/your team's computers. … There's also a web interface, and the files are securely backed up to Amazon S3.”
Source: Y Combinator: Dropbox's application
3 more real answers
Example Shiftwell · fictional startup, for illustration
“Shiftwell fills last-minute cancellations at dental clinics. When a patient cancels, our AI texts the right patients on the waitlist and rebooks the slot, usually within 20 minutes. Think OpenTable's waitlist, but for dentists.”
What a strong answer does: Walk one real example end to end. Skip the architecture unless asked.
Example Shiftwell · fictional startup, for illustration
“A patient cancels a 2pm cleaning. We read the clinic's calendar, rank waitlisted patients by distance, insurance and past response rate, and text the top five. The first to confirm gets the slot and it syncs back to the clinic's software.”
What a strong answer does: Name the one thing that didn't exist before, not a list of features.
DropboxS07 Drew Houston · Written YC application
“Dropbox solves all these needs, and doesn't need configuration or babysitting. … With Dropbox, you hit "Save", as you normally would, and everything just works”
Source: Y Combinator: Dropbox's application
Example Shiftwell · fictional startup, for illustration
“Clinics already have waitlists, but they live on a sticky note. We're the first to fill the slot automatically, without the front desk making a single call.”
What a strong answer does: Be honest. If the hard part is distribution or data, say that.
ApptimizeS13Nancy Hua & Jeremy Orlow · Written YC application
“AB testing for mobile is a technologically harder problem than for websites due to challenges particular to mobile devices.”
Source: Nancy Hua: successful YC S13 application
Example Shiftwell · fictional startup, for illustration
“The hard part isn't the AI, it's integrating with 11 different dental practice systems. We've built connectors for the four that cover 70% of clinics.”
What a strong answer does: Personal, specific and short. A real moment beats a market thesis.
3 more real answers
ApptimizeS13 Nancy Hua & Jeremy Orlow · Written YC application
“We picked this idea because Jeremy had looked for a mobile AB testing solution when working on Drawchat, but couldn't find one.”
Source: Nancy Hua: successful YC S13 application
LagoS21Anh-Tho Chuong · Written YC application, for an idea before their pivot
“We experienced the problem firsthand in several startups.”
Source: Lago blog: How we got into YC
Example Shiftwell · fictional startup, for illustration
“My mom runs a dental clinic. She was losing about $4,000 a month to empty chairs, and her receptionist spent two hours a day calling the waitlist.”
What a strong answer does: One concrete next feature, tied to something users asked for.
Example Shiftwell · fictional startup, for illustration
“Predicting cancellations before they happen. Our data shows Monday 8am slots cancel three times more often, so we'll start overbooking them safely.”
What a strong answer does: Name the exact person, not a market segment.
Example Shiftwell · fictional startup, for illustration
“The office manager at a one- to three-dentist practice. They're judged on chair utilization and don't have time to work the phones.”
What a strong answer does: Separate who pays from who uses, if they're different.
Example Shiftwell · fictional startup, for illustration
“The front desk uses it every day. The practice owner pays for it, because every filled slot is about $180 in revenue.”
What a strong answer does: Evidence, not opinion: usage, payments, waitlists or quotes from users.
CoinbaseS12Brian Armstrong · Written YC application, quoted by YC
“Right now there are about 100,000 bitcoin users despite the relatively immature tools, which is a good indicator of interest.”
Source: YC blog: Coinbase, from YC to IPO
LagoS21 Anh-Tho Chuong · Written YC application, for an idea before their pivot
“At the end of January, before we even had a landing page, 70+ startups had already contacted us (100% inbound) and asked if they could try our product asap.”
Source: Lago blog: How we got into YC
Example Shiftwell · fictional startup, for illustration
“Twelve clinics pay us $299 a month, and none have cancelled. Three found us through word of mouth before we'd done any marketing.”
What a strong answer does: Show the cost of the problem in their numbers.
CoinbaseS12 Brian Armstrong · Written YC application, quoted by YC
“In the bitcoin world, right now people use the open source desktop client which is scary unless you're technical (34 digit hashes are your send/receive addresses).”
Source: YC blog: Coinbase, from YC to IPO
Example Shiftwell · fictional startup, for illustration
“We audited 30 clinics' calendars. The average one loses 9 hours of chair time a week to cancellations, which is about $70,000 a year.”
What a strong answer does: Share an insight you only got by talking to them.
Example Shiftwell · fictional startup, for illustration
“Office managers don't want AI, they want to stop being blamed for empty chairs. So we send the owner a weekly email crediting the front desk.”
What a strong answer does: A real surprise shows you're paying attention.
Example Shiftwell · fictional startup, for illustration
“Patients reply to our texts within 4 minutes on average, but almost never answer a phone call from the clinic.”
What a strong answer does: Rank them, and say which one you're building now.
Example Shiftwell · fictional startup, for illustration
“First, filled slots. Second, no double bookings. Third, insurance checks before the patient arrives. We're building insurance checks next.”
What a strong answer does: Name the real objection and what you're doing about it.
Example Shiftwell · fictional startup, for illustration
“They're scared we'll text patients something wrong. So for the first two weeks, every message needs one tap of approval from the front desk.”
What a strong answer does: An exact number, plus what counts as a user.
PaystackW16Shola Akinlade · Written YC application
“Private Beta. We are piloting with a dozen merchants and we have hundreds of merchants on our waiting list.”
Source: Paystack blog: Paystack's YC application
1 more real answer
PostHogW20James Hawkins & Tim Glaser · YC interview prep notes (founder recap), for a product before their pivot
“We had signed up 400 people in just three weeks … we had 2 companies who said they would pay”
Source: PostHog blog: The YC interview
Example Shiftwell · fictional startup, for illustration
“Twelve paying clinics, 41 front-desk users, and about 3,800 patients texted last month.”
What a strong answer does: Week over week or month over month, and over what period.
GitLabW15Sid Sijbrandij & Dmitriy Zaporozhets · Written YC application
“Over 100.000 organizations are using GitLab. … $1m annual Revenue Run Rate … About 60% in revenue each month.”
Source: GitLab blog: GitLab's application for YC W15
Example Shiftwell · fictional startup, for illustration
“Revenue has grown 22% month over month for the last four months, from $1,500 to $3,600 in monthly recurring revenue.”
What a strong answer does: Paying vs free, and the price.
Example Shiftwell · fictional startup, for illustration
“All twelve clinics pay $299 a month. We have no free tier, just a two-week trial.”
What a strong answer does: Know your funnel cold: demo to trial to paid.
Example Shiftwell · fictional startup, for illustration
“Sixty percent of clinics that take a demo start a trial, and 80% of trials convert to paid.”
What a strong answer does: Name the channel that works and the numbers behind it.
Example Shiftwell · fictional startup, for illustration
“Mostly dental supply reps. We pay them a $200 referral bonus and they've brought in seven of our twelve clinics.”
What a strong answer does: The trigger moment that makes someone switch.
Example Shiftwell · fictional startup, for illustration
“A bad week. We ask every prospect how many cancellations they had last week, and put the dollar figure in front of them.”
What a strong answer does: One or two channels you've tested, not a list of everything.
Example Shiftwell · fictional startup, for illustration
“Supply-rep referrals and dental study clubs, which are monthly meetups of 20 to 40 dentists. We've presented at three and signed two clinics from each.”
What a strong answer does: A number, plus payback time if you know it.
Example Shiftwell · fictional startup, for illustration
“About $350 per clinic, mostly referral bonuses. At $299 a month we earn it back in under six weeks.”
What a strong answer does: Who pays, how much, how often.
DropboxS07 Drew Houston · Written YC application
“The current plan is a freemium approach, where we give away free 1GB accounts and charge for additional storage … maybe ~$5/mo or less for 10GB for individuals and team plans that start at maybe $20/mo.”
Source: Y Combinator: Dropbox's application
GitLabW15 Sid Sijbrandij & Dmitriy Zaporozhets · Written YC application
“Mostly by selling subscriptions that entitle our customers to support and our proprietary GitLab Enterprise Edition. … Our most sold subscription by revenue costs $49 per user per year.”
Source: GitLab blog: GitLab's application for YC W15
3 more real answers
PostHogW20 James Hawkins & Tim Glaser · YC interview prep notes (founder recap), for a product before their pivot
“Given we'd charge $10 per month per user”
Source: PostHog blog: The YC interview
Example Shiftwell · fictional startup, for illustration
“A monthly subscription, $299 per clinic. Next year we'll add a per-filled-slot fee for larger groups.”
What a strong answer does: Bottom-up math: number of customers times price.
The MuseW12Kathryn Minshew & Alex Cavoulacos · Written YC application
“We have a clear step-by-step sense of how we could make $40M/year and market data that suggests a much larger opportunity if we can figure out how to monetize it.”
Source: The Muse: our successful YC W12 application
Example Shiftwell · fictional startup, for illustration
“At $3,600 a year per clinic, every 10,000 clinics is $36 million a year. And that's dentistry alone, before other appointment-based clinics.”
What a strong answer does: A straight answer, including amount and from whom.
Example Shiftwell · fictional startup, for illustration
“No. We're funded by revenue and $20,000 of our own savings.”
What a strong answer does: Monthly spend, in a number.
Example Shiftwell · fictional startup, for illustration
“About $4,000 a month, mostly servers and SMS costs. Neither founder takes a salary yet.”
What a strong answer does: Months of runway, and whether you're near break-even.
Example Shiftwell · fictional startup, for illustration
“About ten months. At our current growth we hit break-even in five.”
What a strong answer does: Name them. 'No competitors' is a red flag.
DropboxS07 Drew Houston · Written YC application
“Carbonite and Mozy do a good job with hassle-free backup, and a move into sync would make sense. … Google's coming out with GDrive at some point.”
Source: Y Combinator: Dropbox's application
PaystackW16 Shola Akinlade · Written YC application
“The incumbents are big co's owned by banks and are not interested in innovating. … Local Non FI's are the real competition”
Source: Paystack blog: Paystack's YC application
Example Shiftwell · fictional startup, for illustration
“Patient messaging tools send reminders, but none fill the slot. The real competitor is the receptionist with a phone and a sticky note.”
What a strong answer does: Pick one and say why. It shows you've thought about it.
GitLabW15 Sid Sijbrandij & Dmitriy Zaporozhets · Written YC application
“GitHub Enterprise and Atlassian Stash are our primary competitors. … We fear Atlassian Stash most since the GitHub Enterprise offering is weak …”
Source: GitLab blog: GitLab's application for YC W15
Example Shiftwell · fictional startup, for illustration
“The biggest practice management system building this as a feature. Our defence is working across every system, not just theirs.”
What a strong answer does: What changed recently, or what's hard that others avoid.
PapercupsKam Leung · YC interview (founder recap), 2020
“[Asked why Flexport hadn't built an internal version of their product:] We didn't have a good answer. … Within 30 minutes we got on the phone with an engineer and got our answer.”
Source: Kam Leung: Turning a maybe into a yes after the YC interview
Example Shiftwell · fictional startup, for illustration
“The integrations are painful. Every dental system is different, so bigger companies skipped this market for easier ones.”
What a strong answer does: One sharp difference a user would notice.
Example Shiftwell · fictional startup, for illustration
“Others send reminders. We actually fill the empty slot, with no staff involved.”
What a strong answer does: Show you see the threats coming.
Example Shiftwell · fictional startup, for illustration
“Patient messaging tools adding a waitlist, and large dental groups building their own in-house.”
What a strong answer does: Start specific, then show how it expands.
1 more real answer
GitLabW15 Sid Sijbrandij & Dmitriy Zaporozhets · Written YC application
“We already declined an acquisition offer from a competitor for $10M because we want to grow this into a large company.”
Source: GitLab blog: GitLab's application for YC W15
Example Shiftwell · fictional startup, for illustration
“We start with independent dentists, where every clinic has this problem. The same problem exists in physical therapy, dermatology and vets, with the same integrations.”
What a strong answer does: Your non-obvious insight. This is often the most important answer.
DropboxS07 Drew Houston · Written YC application
“Competing products work at the wrong layer of abstraction and/or force the user to constantly think and do things.”
Source: Y Combinator: Dropbox's application
GitLabW15 Sid Sijbrandij & Dmitriy Zaporozhets · Written YC application
“An open source development process allows you to market your product for free. It also allows a good product market fit at a low cost.”
Source: GitLab blog: GitLab's application for YC W15
4 more real answers
LagoS21 Anh-Tho Chuong · Written YC application, for an idea before their pivot
“Making Growth teams dependent on Engineers is a lose-lose setup”
Source: Lago blog: How we got into YC
Example Shiftwell · fictional startup, for illustration
“Cancellations aren't random. Two-thirds come from 15% of patients, so we can predict and fill most slots before the patient even cancels.”
What a strong answer does: One logical next step, not a fantasy.
Example Shiftwell · fictional startup, for illustration
“Every appointment-based clinic with a waitlist: physical therapy, dermatology, vets. Same problem, same integrations.”
What a strong answer does: The real story, briefly.
Example Shiftwell · fictional startup, for illustration
“We were roommates at Waterloo and built two side projects together before this. We've worked through a bad launch already.”
What a strong answer does: How long you've known each other matters more than how you met.
Example Shiftwell · fictional startup, for illustration
“In first-year computer science, six years ago.”
What a strong answer does: Clear, non-overlapping roles. Let each founder answer for themselves.
Example Shiftwell · fictional startup, for illustration
“I sell and talk to clinics every day. My co-founder built the product and the integrations.”
What a strong answer does: Have an answer agreed in advance. Hesitating here hurts.
Example Shiftwell · fictional startup, for illustration
“I'm CEO and make the final call on the business. She's CTO and owns every technical decision.”
What a strong answer does: Evidence you've survived something hard together.
Example Shiftwell · fictional startup, for illustration
“We've already been through a failed startup together and are still friends. We both quit our jobs in May to do this full time.”
What a strong answer does: Relevant experience or unusual access to customers.
Example Shiftwell · fictional startup, for illustration
“I grew up working the front desk at my mom's clinic, so I've lived the problem. We also have three dentists advising us.”
What a strong answer does: Something that shows you build fast or don't give up.
Example Shiftwell · fictional startup, for illustration
“My co-founder reverse-engineered a dental system with no public API in a weekend, which is how we got our first clinic.”
What a strong answer does: The role that unblocks growth, and why.
DropboxS07 Drew Houston · Written YC application
“I have several leads, have been networking aggressively, and fully intend to get someone else on board … I'm aware that the odds aren't good for single founders, and would rather work with other people anyway.”
Source: Y Combinator: Dropbox's application
Example Shiftwell · fictional startup, for illustration
“A second engineer to build more integrations. Each new system we support opens up about 10% more clinics.”
Q44Hard questions & next steps
What a strong answer does: Real, owned, and what you learned. No humble-brags.
Example Shiftwell · fictional startup, for illustration
“We spent two months building analytics nobody asked for. Now we don't build anything until three clinics request it.”
Q45Hard questions & next steps
What a strong answer does: Name the biggest one and your specific plan.
Example Shiftwell · fictional startup, for illustration
“Integrations. Larger systems can take months to approve partners, so we're signing clinics on the systems we support first.”
Q46Hard questions & next steps
What a strong answer does: Show you're thinking ahead.
Example Shiftwell · fictional startup, for illustration
“Support. Every new clinic needs hand-holding for the first week, and right now that's me.”
Q47Hard questions & next steps
What a strong answer does: Honesty wins. Name the risk and what you're doing about it.
Example Shiftwell · fictional startup, for illustration
“If the biggest practice system builds this themselves and blocks our integration. That's why we're adding other systems fast, so no one company controls our fate.”
Q48Hard questions & next steps
What a strong answer does: Yes, but show conviction in the problem.
Example Shiftwell · fictional startup, for illustration
“Yes, if the data says so. But we're sure about the problem: empty chairs cost clinics real money.”
Q49Hard questions & next steps
What a strong answer does: Specific goals with numbers for the next three months.
Example Shiftwell · fictional startup, for illustration
“Get to 40 paying clinics and $12,000 in monthly revenue by Demo Day, and launch our fifth integration.”
Q50Hard questions & next steps
What a strong answer does: What you'll get, specifically, that you can't get alone.
Example Shiftwell · fictional startup, for illustration
“To move faster on two things we're bad at: raising money and selling to larger dental groups. The batch is full of founders who've already solved both.”
MixpanelS09