I spent weeks reading everything YC has ever published about what they look for. here are 9 things that would have changed how I thought about the application

The YC red flags in applications: → Founders who haven't talked to users → Founders who can't say their churn rate → Founders who describe technology before problems → Founders who can't disagree with each other in the room One of these: a concern. Two or more: almost always a rejection.

The compounding math from "Startup = Growth" - A startup growing at 5% per week: Year 1: 12.6x growth. Year 2: 158x growth. - Growing at 10% per week: Year 1: 142x growth. The difference between 5% and 10% weekly: Not 2x better. 11x better in year 1. This is why YC targets 10% week-over-week

A few words on how to write a YC application backed by evidence. Your application shouldn't sound like a pitch deck. It should sound like a founder who understands the problem. Look at what successful founders could actually show: - Dropbox: A simple explanation of what the product does. No need to dress up file syncing as a revolution. - Stripe: A clear product proposition: APIs for online payments. Explain what you're building and why it matters. - DoorDash: 100+ interviews with small businesses, then 150+ paying customers and over $10K in sales in its first month. Notice the difference. They weren't just describing a big market. They were showing what they'd learned, what they'd built, and what happened when real customers used it. And you don't need revenue to apply. YC says around 40% of the companies it funds in a typical batch are still at the idea stage, and most have no revenue. If you're early, show what you've learned from users. If you've launched, show what users are doing. If you're growing, show the numbers. Don't invent traction you don't have. Replace vague claims with specific evidence. Your application should make it easy to understand what you're building, who needs it, and what you've learned so far.

Someone on the team needs to be able to build the software. If you are a non-technical solo with no product and no revenue: → The hole dominates the form. If a founder writes the code: → The “who builds” question shrinks. Accepted software companies usually have a builder in the founding team.

Steal this YC habit: watch a user try the product in silence. → Pauses and wrong clicks reveal the real problems. → Explaining hides the friction you need to fix. → The notes become the next thing you ship. run one session with your microphone off and ship from what you see.

Series A firms pass when gross margin is negative and there is no clear path to fix it. → Losing money on every customer gets worse as you grow. → Early high delivery costs or deep discounts need a dated improvement plan. → A promise of “software margins later” is not enough. calculate current gross margin and name the one cost you will cut in the next 60 days

One paying customer answers three questions at once: - who has the problem, - whether they will pay, and - that you can close. If your application only has conversations: → You still have to prove all three separately. If your application has a real payment: → Those three questions shrink and the partner can focus on the team and the wedge. Put the amount, the date, and the job title of the person who paid. That is the whole sentence.

The "research phase" trap that delays YC applications forever: "We're still doing customer discovery." After 6 months. Customer discovery should take 4 weeks. Not 6 months. 20 conversations. Write down the patterns. Pick the most painful. Build the minimum thing. The founders stuck in "research phase": are usually avoiding the moment when the market tells them if they're right or wrong.

YC W27 is open. Apply if you’re early. On-time deadline is November 2 at 8pm PT. You get a decision by December 11. Late applications are still read. Most founders wait for the product to look finished. You don’t have to. About 40% of the companies YC funds are still just an idea. Most have no revenue. Only about 7% had more than $50k monthly revenue when they got in. Solo founders are now up to 19% of the batch. Half the companies in a typical batch applied more than once. Apply if you can: • show a product that works for one real user • say who is stuck, and what it costs them, in one sentence • apply while the numbers are still small • start before you feel ready • treat a no as a clearer next try The batch runs January to March 2027 in San Francisco. You get the $500K standard deal, $12M in partner credits, partners in the room, and Demo Day. If you can name the person with the problem, you’re early enough.

The 90-day sprint before your YC application: Day 1–30: Talk to 30 potential users. Don't build anything yet. Just listen. Day 31–60: Build the minimum thing that solves the most painful problem you heard. Day 61–90: Get 3 people to pay for it. Any amount. Real money. Submit the application on day 91. That application will be unrecognizable compared to the one you would have written on day 1.

Write this on the whiteboard: the weekly growth rate of one real metric. → Use revenue if you charge, or people who did the core job if you do not. → Keep the same definition every week. → Decide what changes when the number misses. put the number and definition where the team sees it and review every Friday

Start the Series A process with at least 6 months of cash left, not 3. If you begin when you have 3 months: → You are negotiating while the company is already stressed. If you begin with 6–9 months: → You can walk away from a bad term sheet. The raise takes 8–16 weeks. Build that time into the plan, not into the emergency.

They fund founders harder than they fund ideas. If your application has a beautiful idea and a mushy team: → You optimized the thing they expect to change. If the team looks like it can survive a pivot: → You optimized what they actually buy. Accepted means people. The idea is evidence those people are sharp.