YC turns builders
into formidable founders[1]
into formidable founders[1]
[1] “A formidable person is one who seems like they’ll get what they want, regardless of whatever obstacles are in the way.”
— Paul GrahamDuring YC
Sam was part of YC's inaugural batch in S05 and founded OpenAI as YC Research in 2015.
Brian, Joe, and Nate did YC in W09.
The Collison brothers did YC twice—first in W07 and then in S09, when they started Stripe.
Fred and Brian met on Reddit and did YC in S12.
Andy, Stanley, Tony, and Evan did YC in S13.
Alexandr and Lucy did YC S16 and pivoted during the batch.
Arash and Drew started Dropbox at MIT and did YC in S07.
Alexis and Steve were in the inaugural YC batch in S05.
Apoorva, Max, and Brandon did YC in S12.
Sid and Dmytro did YC in S14.
Tarek and Luana did YC in W19.
Haya and Amjad interviewing for the YC W18 batch.
Michael, Justin, Kyle, and Emmett in YC W07.
Now
Sam built OpenAI into a $500B company.
Airbnb went public in 2020 at an over $100B valuation.
Stripe is now the internet's $107B payments backbone.
Coinbase went public in 2021 at a $86B valuation.
DoorDash went public in 2020 at a valuation of $39B.
In 2025, Meta acquired 49% of Scale for over $14B.
Dropbox had the biggest tech IPO of 2018 at a $9B valuation.
Reddit went public in 2024 at a $6.4B valuation.
Instacart went public in 2023 at a $10B valuation.
GitLab went public in 2021 at an $11B valuation.
Kalshi reached an $11B valuation in 2025.
Replit became a leading AI coding platform valued at over $9B.
Twitch was acquired by Amazon for nearly $1B.
OpenAI
Airbnb
Stripe
Coinbase
DoorDash
Scale AI
Dropbox
Reddit
Instacart
GitLab
Kalshi
Replit
Twitch
In 2005, Y Combinator developed a new model of startup funding. Four times a year we invest $500k in a select group of startups. They move to San Francisco for three months, where we work intensively with them to get the company into the best possible shape, before they present to a large audience of investors on Demo Day.
But YC doesn’t end on Demo Day. We and the YC alumni network continue to help founders for the life of their company, and beyond.
In Founders’ Words
YC compresses months of growth into weeks. 
The sense of urgency is so infectious among founders that it becomes the most productive period in most people's lives. 
The sense of urgency is so infectious among founders that it becomes the most productive period in most people's lives. It's a community of founders that you can't find anywhere else. 
It feels like having the entire world at your back—from Partners to batchmates. 
It feels like having the entire world at your back—from Partners to batchmates. Being surrounded by the top 1% of founders in the world just completely resets the bar. 
You leave with a completely new sense of how fast 'fast' can be.
You leave with a completely new sense of how fast 'fast' can be. Be in the room with…
All partners were
YC founders first
Garry TanPosterous, S08
Co-founder of Posterous (acquired by Twitter) and Initialized Capital. Early engineer at Palantir, designed company logo.
Harj TaggarAuctomatic, W07
Co-founder and CEO of Triplebyte (acquired by Karat) and Auctomatic (acquired by Live Current Media). Graduated from Oxford.
Jared FriedmanScribd, S06
Co-founder of Scribd, one of the top 100 sites on the web. Harvard CS dropout.
Aaron EpsteinCreative Market, W10
Co-founder of Creative Market, generating over $100M in sales for independent creators worldwide.
Diana HuEscher Reality, S17
Co-founder and CTO of Escher Reality (acquired by Niantic). Shipped AR tech for Pokémon GO to 100M+ users and grew up in Chile.
Gustaf AlströmerHeysan, W07
Led Growth at Airbnb for 4.5 years. Co-founder of Heysan. Previously Head of Growth at Voxer.
Nicolas DessaigneAlgolia, W14
Co-founder of Algolia, a Search API used by millions of developers. PhD in Computer Science.
Tom BlomfieldGoCardless, S11
Co-founder of Monzo (£500M raised, 10% UK population). Founded GoCardless. Awarded OBE in 2019.
Brad FloraPerfect Audience, S11
Co-founder and CEO of Perfect Audience (acquired by Marin Software). Active angel investor and Slate contributor.
Pete KoomenOptimizely, W10
Co-founder of Optimizely, grew to $100M+ ARR before acquisition. Master's in CS from UIUC.
Ankit GuptaReverie Labs, W18
Co-founder and CTO of Reverie Labs (acquired by Ginkgo Bioworks). Deep learning researcher in language, vision, and biology.
Tyler BosmenyClever, S12
Co-founder and CEO of Clever (acquired for $500M). Used by 60% of US students.
David LiebBump, S09
Co-founder and CEO of Bump (150M+ users, acquired by Google). Co-founder of Google Photos (1B+ users).
Andrew MiklasPagerDuty, S10
Co-founder & CTO of PagerDuty (NYSE:PD), the first incident management platform and used by half of the Fortune 500. University of Waterloo & Toronto grad.
Harshita AroraAtoB, S20
Co-founder of AtoB, a fintech startup worth $800M. Moved from India to SF on an O-1 visa at 16 y/o.
Jon XuFutureAdvisor, S10
Co-founder and CTO of FutureAdvisor (acquired by BlackRock). Built robo-advisor platform for financial institutions. MIT EECS grad.
