YC turns builders into formidable founders

Airbnb

Brian, Joe, and Nate did YC in W09.

Airbnb went public in 2020 at an over $100B valuation.

OpenAI

Sam was part of YC's inaugural batch in S05 and founded OpenAI as YC Research in 2015.

Sam built OpenAI into a $500B company.

Stripe

The Collison brothers did YC twice—first in W07 and then in S09, when they started Stripe.

Stripe is now the internet’s $107B payments backbone.

Coinbase

Fred and Brian met on Reddit and did YC in S12.

Coinbase went public in 2021 at a $86B valuation.

DoorDash

Andy, Stanley, Tony, and Evan did YC in S13.

DoorDash went public in 2020 at a valuation of $39B.

Scale AI

Alexandr and Lucy did YC S16 and pivoted during the batch.

In 2025, Meta acquired 49% of Scale for over $14B.

Dropbox

Arash and Drew started Dropbox at MIT and did YC in S07.

Dropbox had the biggest tech IPO of 2018 at a $9B valuation.

Reddit

Alexis and Steve were in the inaugural YC batch in S05.

Reddit went public in 2024 at a $6.4B valuation.

Instacart

Apoorva, Max, and Brandon did YC in S12.

Instacart went public in 2023 at a $10B valuation.

GitLab

Sid and Dmytro did YC in S14.

GitLab went public in 2021 at an $11B valuation.

Kalshi

Tarek and Luana did YC in W19.

Kalshi reached an $11B valuation in 2025.

Replit

Haya and Amjad interviewing for the YC W18 batch.

Replit became a leading AI coding platform valued at over $9B.

Twitch

Michael, Justin, Kyle, and Emmett in YC W07.

Twitch was acquired by Amazon for nearly $1B.

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.

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.

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.

Be in the room with…

• Brian Chesky, Airbnb
• Sam Altman, OpenAI
• Greg Brockman, OpenAI
• Michael Truell, Cursor
• Paul Graham, Y Combinator
• Guillermo Rauch, Vercel
• Dylan Field, Figma
• Emmett Shear, Twitch
• Tony Xu, DoorDash

“This is the greatest time ever to start a company. YC is where some of the world’s most ambitious builders come to learn fast, take on hard problems, and get going.”

Jensen Huang, founder and CEO of NVIDIA

All partners were YC founders first

• Garry Tan, Posterous, S08, Co-founder of Posterous (acquired by Twitter) and Initialized Capital. Early engineer at Palantir, designed company logo.
• Harj Taggar, Auctomatic, W07, Co-founder and CEO of Triplebyte (acquired by Karat) and Auctomatic (acquired by Live Current Media). Graduated from Oxford.
• Jared Friedman, Scribd, S06, Co-founder of Scribd, one of the top 100 sites on the web. Harvard CS dropout.
• Aaron Epstein, Creative Market, W10, Co-founder of Creative Market, generating over $100M in sales for independent creators worldwide.
• Diana Hu, Escher 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 Alströmer, Heysan, W07, Led Growth at Airbnb for 4.5 years. Co-founder of Heysan. Previously Head of Growth at Voxer.
• Nicolas Dessaigne, Algolia, W14, Co-founder of Algolia, a Search API used by millions of developers. PhD in Computer Science.
• Tom Blomfield, GoCardless, S11, Co-founder of Monzo (£500M raised, 10% UK population). Founded GoCardless. Awarded OBE in 2019.
• Brad Flora, Perfect Audience, S11, Co-founder and CEO of Perfect Audience (acquired by Marin Software). Active angel investor and Slate contributor.
• Pete Koomen, Optimizely, W10, Co-founder of Optimizely, grew to $100M+ ARR before acquisition. Master’s in CS from UIUC.
• Ankit Gupta, Reverie Labs, W18, Co-founder and CTO of Reverie Labs (acquired by Ginkgo Bioworks). Deep learning researcher in language, vision, and biology.
• Tyler Bosmeny, Clever, S12, Co-founder and CEO of Clever (acquired for $500M). Used by 60% of US students.
• David Lieb, Bump, S09, Co-founder and CEO of Bump (150M+ users, acquired by Google). Co-founder of Google Photos (1B+ users).
• Andrew Miklas, PagerDuty, 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 Arora, AtoB, 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 Xu, FutureAdvisor, S10, Co-founder and CTO of FutureAdvisor (acquired by BlackRock). Built robo-advisor platform for financial institutions. MIT EECS grad.
• Chris Golda, BackType, S08, Co-founder and CEO of BackType (acquired by Twitter). Launched Twitter’s Ad Center, growing revenue to over $1B.
• Grey Baker, Pincites, S23, Co-founder of Pincites (acquired by Filevine). Previously co-founded Dependabot (acquired by GitHub) and led product and engineering at GoCardless.