YC Mock Interview: The 5 Biggest Questions You Will Get Asked By Y Combinator and How To Answer Them

Who I Am and Why You Should Practice With Me

I am Arjun Mahadevan, founder and CEO of Dula.com, a YC batch startup in New York City that has raised over 13 million dollars. I have sat in this exact hot seat before, which is why I care about getting you ready for it. When you are staring down a fast 10 minute YC interview, the difference between a crisp answer and a fuzzy one can swing the conversation. I have felt the clock ticking, the intensity in the room, and the pressure to communicate clearly. That is why I built this live run through that you can follow along with and actually practice.

A quick word on context. Y Combinator is the startup accelerator that has funded companies like Airbnb, Dropbox, Stripe, Coinbase, and many more that you probably use daily. YC interviews are short, intense, and very direct, usually around 10 minutes, with one or more partners asking questions as fast as you can answer them. There is little fluff. There are no filler slides. You need to explain exactly what you do, how far along you are, why you are the right people, how you get customers, and how you compare against real competitors. That is the game.

How To Use This Mock Interview Format

Practice with me. After each question below, a timer would appear in the video. Since you are reading, treat the pause markers as intentional stops. Hit pause mentally, write or speak your answer out loud, then compare it with the coaching in each section. The point is to train the exact muscle you will use in the interview: fast, literal, precise communication under pressure.

Visual cue if you were watching: a countdown timer pops in after every prompt. I intentionally leave space so you can answer. Then I jump back in with the framework, the example, and the common mistakes to avoid. Make this interactive for yourself. Do not just skim. Say it out loud, time yourself, then refine.

Question 1: What Are You Working On?

OK, how did that feel? That single question kicks off almost every YC interview. It is simple on paper and surprisingly hard in real time. This is the very first question that every partner asks in any interview. It sets the tone for the whole conversation because your answer reveals your clarity of thought, how well you understand your own product, and whether you can communicate without fluff.

Here is the thing. This is actually the only question that you can fully prepare for and practice to the letter. So do it. If there are multiple founders, pick one person. One person should answer this, and they should answer it as literally as possible.

How To Answer Literally, Without Jargon

Do not use jargon like you are transforming or revolutionizing an industry. Spell out exactly what you do in plain English. If someone overheard your answer in a coffee shop, they should be able to repeat it back and get the core of your product right.

For example, with Dula, I would not say we are revolutionizing business formation. That language is vague and sounds like every other pitch. I would say we get you an LLC in all 50 states, an EIN, set up your bank account, and do your bookkeeping and taxes in one place for 3,000 dollars per year. That is literal. That is testable. That is a product you can buy.

Most Common Mistake To Avoid

The most common mistake here is using too much jargon or too many buzzwords. Do not state your grand vision to change humanity. Just state what you do with zero ambiguity. If you start with a sweeping mission, partners will cut in and ask again: what do you do? Answer that first, then let the rest of the interview pull in your vision if there is time.

Question 2: What Is Your Progress So Far?

This is where you prove you are a doer, not a dreamer. The more specific the better. Think in numbers, not adjectives. YC partners listen for traction signals that map to real customer behavior and real product usage.

The Formula That Works

Lead with your most impressive metric. If you do not know your most impressive metric well, big red flag. As a startup, and YC hammers this point home, you need to have your key metric. That could be recurring revenue, it could be product usage, activation, retention, or something else that clearly ties to customer value. Ideally it is revenue. Revenue is the North Star because it is a hard signal that people pay for what you built.

After that, in bullet point style, follow with other metrics. Keep it tight. Here is an example answer:

• We have 1 million in annual recurring revenue.
• We are growing 10 percent week over week.
• We have 1,000 paying customers.

That took two sentences and used precise numbers, leading with the most impressive metric. No filler. No backstory. Just traction.

What Not To Do

Do not lead with a long story about how you met your cofounder and what you have been building. No. They asked how far along are you. Be precise. Get to the point. The interview flies by in 10 minutes, and every second you spend on backstory is a second you do not spend on proof.

If You Do Not Have Revenue Yet

If you do not have revenue, you should ideally have product usage. Talk about active users, retention, cohorts, weekly actives, or shipped features that unlocked a new usage pattern. If you do not have product usage, then you need to highlight how quickly you have been building, because YC wants to see you can move fast. Speed compounds in the early days. They are looking for signs that you can turn feedback into product quickly and repeatedly.

Say what shipped, when it shipped, what changed because of it, and what is next. Treat time as the axis you will win on until revenue kicks in.

Question 3: What Is Your Unique Insight?

This is the why you question in disguise. It is probing for founder market fit. Why are you the best person to solve this problem and to build this company, and what have you learned that is non obvious. YC wants to understand why you know this market and problem better than anyone else in the world. They are testing for a real earned insight that changes how you build.

How To Frame Your Non Obvious Insight

The formula here is simple. Think hard about a non obvious insight you have come across. Then start with a phrase like we discovered that or the non obvious insight is and fill in the blank. This sets you up to deliver something crisp and surprising.

Here is an example from Dula. Our non obvious insight is that we realized the buyer journey for international founders is backwards compared to founders in the United States. For founders in the US, the sequence is: pick the name of my LLC, then form the LLC, then get a bank account, then bookkeeping, then taxes. That is the default order because the system is familiar, the forms are known, and the friction shows up later in the stack.

But for international founders, it is flipped. International founders have more questions about taxes than they do about formation. They are thinking about tax residency, treaty rules, how to pay themselves, and how not to mess up compliance before they even select an entity. Yet almost every alternative in the market was leading with formation as if that was the main problem. So we flipped the script. That was our non obvious insight, and we learned it from talking to customers over and over.

Common Mistake To Avoid

Do not just describe the market. Really sit down and think what is non obvious. You want the partner to walk away thinking, huh, I learned something new from that answer. If you cannot find a unique insight, here is the harsh truth. You might not have done enough research or you are not truly doing something that is non consensus enough.

And why does that matter? If it is not non consensus enough, and other people are doing the exact same thing in the exact same way, competition will be fierce. That does not mean you cannot succeed. But the idea with a unique insight is you have a secret you are in on before the rest of the world knows. That secret changes your product roadmap, your distribution, or your business model in a way that compounds.

Question 4: How Do You Plan To Get Users?

How will you get your first 1,000 customers. YC partners are testing whether you have a concrete plan to acquire customers. Because here is the truth: most companies do not die because they fail to build the product. Most companies die because they fail to repeatedly acquire customers at a low enough customer acquisition cost. Say that four times.

The Acquisition Plan They Want To Hear

You need to have a plan to acquire customers. Describe as tactfully and specifically as possible what your repeatable process is. Name the channels. Show the depth. Go one level deeper than just label words.

For Dula, for example:

• A third of our acquisition is through Google paid ads. We capture search based intent like how to start LLC in the US. That intent signal means people are already in motion.
• A third of our acquisition is through channel partnerships with communities, courses, and influencers who teach people how to start a business on Shopify. We give them a commission so incentives are aligned. They educate, we handle the back office.
• A third of our acquisition is through word of mouth. Founders know founders. We build a great product, they tell their friends, and that compounding loop lowers our blended CAC over time.

Short, crisp, precise, to the point.

Be Specific, Not Broad

The common mistake here is to be too broad. Be specific. You noticed how I named the channels, and I went one level deeper. I did not just say Google Ads. I gave the keyword. I did not just say partnerships. I talked about the type of partner and the context, like Shopify focused creators and communities. And I did not just say word of mouth. I said why it works. I said founders know founders.

Question 5: Who Are Your Main Competitors and Why Are You Different?

This is a test of your market knowledge and your confidence. Never say you do not have competitors, because you always will have competitors. Even if a market is new, people are solving the problem some other way. The status quo is a competitor. DIY is a competitor. A spreadsheet is a competitor.

How To Answer With Clarity

Name exactly the top one to two competitors. Then state your key differentiator in one sentence. State your right to win, or why you are different. Keep it clean.

Here is an example we get a lot. People ask, what about Stripe Atlas, which is a phenomenal company by the way. Anyone helping entrepreneurs, rising tide lifts all boats, I am in full support of. But here is how we are different from Stripe Atlas.

• Stripe Atlas focuses on venture backed C Corps. We focus on solopreneurs or LLC. Different customer, different needs.
• Stripe Atlas offers formation. We offer more downstream services like bookkeeping, taxes, and ecommerce analytics for Shopify entrepreneurs versus a broad based solution for tech or venture backed founders.

Name the competitor. Name your differentiator in one clear sentence. Do not say you do not have competition.

The Reality About Competition

Here is the truth. If you do not want competition, you should not leave your room. You should stay inside all day. And you definitely should not start a startup. There will always be competition in a space where there is an opportunity to build something cool for customers.

That Is Time. Now Go Again.

There we go. I hope you actually pressed pause and ran your answers. You can also go back, restart, and practice these questions again. Practice makes perfect, especially when the format rewards sharp, repeatable answers.

The Three Biggest Things To Do In A YC Interview

I have a separate video on this, but here are the three biggest things, summarized exactly the way I want you to remember them:

• Know your answer to that first question.
• Know the three things you want to share in the interview no matter what, because time is going to fly.
• Be concise, avoid jargon and buzzwords, and answer the question directly.

If you hold those three constraints, you will sound sharper, you will keep control of your message, and you will make it easier for the partners to say yes.

Bonus: A Small Easter Egg For You

By the way, here is a little Easter egg. If anyone watching this actually gets a YC mock interview, I want to pay it forward. So if you made it this far and you have gotten a YC mock interview, you can email me. It is arjunula.com saying hey, I have got a mock interview and I would love to do a mock interview with you.

I hope this does not go too viral because then I will be doing a lot of mock interviews. But if it helps you get sharper and win, that is time well spent.

If This Helped, Here Is How To Keep Going

That is a wrap. Thank you so much for reading. If you found value here, please like, subscribe, and turn on notifications wherever you follow along. I would love to put out more content that provides value and hear your feedback.

Also, if you are applying to YC or scaling a business, schedule a demo below. I would love to see if Dula can be part of your journey and take care of your back office so you can focus on what you do best while Dula handles the rest.

Final Takeaways

Keep the order. Keep the pacing. Keep the clarity. Answer literally what you do. Lead with your best metric. Share the non obvious insight you earned. Name how you acquire customers with channel level detail. Acknowledge your competitors and state your right to win in one sentence.

Do that, and when the clock starts in a YC interview, you will not just survive the next 10 minutes. You will drive them.