Startup Corner #18: Think You’re Ready to Build? Fill This Out First.
A founder’s guide to the best clarity exercise you’re not using yet
Hey friends,
When a founder asks me for feedback on their startup idea, I usually suggest something that almost always surprises them:
Fill out the Y Combinator application.
Not necessarily because I think they should apply (though I often do).
But because the questions in that application force a kind of clarity that’s hard to get any other way.
I’ve come to believe it’s one of the simplest, highest-leverage thinking exercises a founder can do.
It’s free. It’s public. And it’s brutally, beautifully direct.
If you fill it out with seriousness — even if you never submit it — you’ll think more clearly about your startup in an afternoon than you might in six weeks of building in a vacuum.
Let’s talk about why that is — and break down how to approach the questions in a way that actually improves your thinking.
There are two scenarios here — and both are a win.
Scenario 1: You apply and get in. Great. You get access to one of the best founder communities in the world, plus funding, mentorship, and momentum. No downside there.
Scenario 2: You don’t apply — or you apply and don’t get in. And yet... you still win.
Because to even fill out that application, you have to answer some of the most brutal, clarifying questions a founder can face:
What are you building — and why?
Who are your users? How many are there?
How do you know they care?
Why now?
Who are your competitors — and why will you win?
What’s your unfair advantage?
It’s one thing to pitch casually.
It’s another to write it down with no fluff.
The YC app forces the latter.
The form is a mirror
The YC application works because it asks the right questions — not in the way investors might phrase them in a meeting, but in the way founders should be asking them of themselves from day one.
At first glance, the form looks simple. A dozen or so short fields. No pitch deck. No hype.
But what makes it powerful is that it forces written clarity.
And written clarity is where most startup ideas get exposed — or strengthened.
Let’s walk through some of the key questions — not just what they say, but what they mean, and how you can approach them to sharpen your startup strategy in real time.
1. “What are you building?”
This sounds basic, but it’s one of the hardest questions to answer honestly.
What they’re really asking: Can you explain this to a stranger in one sentence — without hiding behind buzzwords?
If your answer includes “platform,” “AI-powered,” “network effects,” or “end-to-end,” take a beat. Strip it back.
Try:
“We help small accounting firms auto-generate monthly reports for clients.”
or
“We’re building a new way for teachers to create lesson plans using real-time student data.”
Your job here is to make someone say, “Oh. Got it.” Not “Hmm… sounds interesting.”
🧠 Founder prompt: How would you describe your product to a non-technical friend who’s smart but tired?
2. “Who are your users, and what problem are you solving for them?”
What they’re really asking: Do you know your customer — and their pain — better than they do?
This isn’t about personas or segments. It’s about felt pain — what someone’s doing today, how they’re coping, and why it’s not enough.
Avoid vague labels like “creators” or “B2B SaaS buyers.” Zoom in:
“Freelance content marketers managing 5+ clients who hate tracking deliverables in spreadsheets.”
Once you do that, you can focus your messaging, prioritize features, and actually sell something people care about.
🧠 Founder prompt: If I called one of your users tomorrow and asked, “What frustrates you about this part of your work?”, what would they say — in their own words?
3. “How do you know people want this?”
What they’re really asking: Is this a hunch, or are people pulling it out of your hands?
YC knows that early traction doesn’t have to be huge. It just has to be real.
That means:
100 survey responses where 40 people said “please build this”
10 people using a Notion prototype
3 companies paying for a manual version
1 weekend launch with 300 signups and zero marketing
If your answer is “We don’t have proof yet, but we’re pretty sure…” — pause. What signal can you create this week?
🧠 Founder prompt: Where is someone already spending time or money to solve this? If you disappeared tomorrow, what problem would they still need to solve?
4. “Why now?”
What they’re really asking: What changed — in tech, culture, or behavior — to make this startup possible (or urgent) today?
This is the momentum test. Great ideas often fail in the wrong moment — or explode in the right one.
So make your case:
“Open banking APIs only became widely available last year — now we can do X in minutes instead of weeks.”
“Remote work made this a top-3 pain point instead of a minor annoyance.”
🧠 Founder prompt: What would have made this idea impossible — or less interesting — five years ago?
5. “Who are your competitors, and what do you do better?”
What they’re really asking: Are you grounded in reality — or in love with your own pitch?
It’s tempting to say “no one’s doing this,” but that’s rarely true. People are always solving the problem — the question is how.
YC wants to know that you’re realistic, not arrogant. So say:
“Our users are duct-taping Zapier + Airtable + Slack. It works, but it’s messy. We replace it with a clean, 3-click flow.”
Or:
“X and Y do parts of this, but they’re built for enterprises. We’re targeting small teams with a 10-minute setup.”
🧠 Founder prompt: What would someone use instead of you today? Why does that solution suck just enough for them to switch?
6. “What’s your insight or unfair advantage?”
What they’re really asking: Why are you the one who sees this clearly — and can execute better than anyone else?
This is your chance to show depth. Not ego — earned insight.
Maybe it’s:
A personal pain point
A weird skill combo
A background in a “boring” industry
A unique distribution loop you discovered early
Think of it as: what do you know that others don’t yet realize is valuable?
🧠 Founder prompt: What would your competitors dismiss as irrelevant — but you know is critical to getting this right?
I think that’s why this exercise matters so much.
Most founders walk around with half-formed answers. Fuzzy confidence. A vibe of conviction.
But the YC questions require you to sharpen the edges.
They turn "I have an idea" into "Here’s what it is, who it’s for, and why it matters — in 300 words or less."
You start seeing where you’re strong.
More importantly, you see where you’re hand-waving.
When you take the application seriously, something shifts.
You think deeper about your market.
You get clearer about your customer.
You start to notice the gaps in your story — the places where your logic skips steps or your assumptions aren’t rooted in reality.
And from there, you can actually improve.
That’s why I don’t see the YC app as a gatekeeping form.
I see it as a thinking framework.
A self-imposed pressure test.
A mirror you hold up to your own clarity.
So here’s the takeaway:
Even if you’re not raising.
Even if you’re not in YC’s sweet spot.
Even if you’re still early.
Go fill out the application anyway.
Use it as a forcing function. A guided audit. A way to think three levels deeper about what you’re actually building.
Worst case? You walk away with clearer thinking and a sharper story.
Best case? You’re more ready than ever — for YC or for whatever path you choose.
You don’t need to be in the batch to get the benefit.
You just need to sit with the questions.
— RB
Startup Corner