People

Founders

Trevor Blackwell
Founder, Retired
Trevor Blackwell is a roboticist who in 2007 built the first dynamically balancing biped robot. He has published papers on congestion control in high speed wide area networks, signalling protocol architecture, and file system performance. He has a BEng from Carleton, and a PhD in Computer Science from Harvard.
Paul Graham
Founder, Retired
Paul Graham is the author of On Lisp (1993), ANSI Common Lisp (1995), and Hackers & Painters (2004). In 1995, he and Robert Morris started Viaweb, the first SaaS company, which in 1998 became Yahoo Store. In 2002 he discovered a simple spam filtering algorithm that inspired the current generation of filters. He has an AB from Cornell and a PhD in Computer Science from Harvard.
Jessica Livingston
Founder, Retired
Jessica Livingston was previously VP of marketing at investment bank Adams Harkness, where she managed an award-winning rebranding of the company. She is the author of Founders at Work (2007), a book of interviews with startup founders. She has a BA in English from Bucknell.
Robert Morris
Founder, Retired
Robert Morris is a professor of computer science at MIT, where he is a member of the PDOS group. He has published extensively on wireless networks, distributed operating systems, and peer-to-peer applications. In 1988 his discovery of buffer overflow first brought the Internet to the attention of the general public. He has an AB and PhD in Computer Science from Harvard.

President & CEO

Garry Tan
President & CEO
Garry Tan is president and CEO of Y Combinator. He was a partner at Y Combinator from 2011 to 2015, where he built key parts of the YC experience for founders including Bookface and the Demo Day website. Garry is the co-founder of Initialized Capital and Posterous (YC S08), a blog platform acquired by Twitter, and prior to that, he was an early designer and engineering manager at Palantir (NYSE:PLTR), where he designed the company logo. Garry holds a BS in Computer Systems Engineering from Stanford.

Group Partners

Gustaf Alströmer
Group Partner
Gustaf Alströmer is a Group Partner at YC. He spent 4.5 years at Airbnb where he worked as a Product Lead on the Growth team, a team he helped start in 2012. Prior to Airbnb, Gustaf was Head of Growth at Voxer, and before that, he was CEO & co-founder of Heysan, which was part of the YC W07 batch.
Tom Blomfield
Group Partner
Tom Blomfield is a Group Partner at YC. He was co-founder of Monzo, one of the first app-based challenger banks in the UK. Monzo raised more than £500m, counts 10% of the UK population as customers, and was the #1 recommended brand in the UK for two years running. Previously, he founded GoCardless (YC S11), an online payments processor for the Direct Debit system. In 2013, he was nominated as one of the Top 5 Entrepreneurs Under 30 by the European Commission, and in 2019 he was awarded an OBE for increasing competition in the banking sector.
Paul Buchheit
Group Partner
Paul Buchheit is a Group Partner at YC and the creator of GMail. While at Google he also built the prototype for AdSense and came up with Google’s famous slogan “Don’t be evil.” In 2007 he was one of the founders of Friendfeed, which in 2009 became Facebook’s largest acquisition to date. He has a BS and MS in Computer Science from Case Western Reserve University.
Dalton Caldwell
Managing Director, Architect and Group Partner
Dalton Caldwell is Managing Director, Architect and Group Partner at YC. He was the cofounder and CEO of imeem (acquired by MySpace in 2009), and the cofounder and CEO of App.net. He has a BS in Symbolic Systems and a BA in Psychology from Stanford University.
Nicolas Dessaigne
Group Partner
Nicolas Dessaigne is a Group Partner at YC. He was the co-founder of Algolia (YC W14), a growth stage Search API used by millions of developers. He led the company as CEO up to 350 people before hiring a successor in 2020. He is still very involved in the success of Algolia as Board Director. Originally from France, he currently lives in Oakland, CA with his wife and 3 kids. He has a PhD in Computer Science from the University of Nantes.
Aaron Epstein
Group Partner
Aaron Epstein is a Group Partner at YC. He was co-founder of Creative Market (YC W10), a marketplace for graphic design assets, which he sold to Autodesk in 2014 and spun out as an independent startup again in 2017. Aaron founded the company to make beautiful design simple and accessible to everyone, and has since helped generate more than $100M in sales for independent creators around the world. He has a BS in Business from the University of Maryland.
Brad Flora
Group Partner
Brad Flora is a Group Partner at YC. He was co-founder and CEO of Perfect Audience, an ad network funded by Y Combinator in 2011, acquired by Marin Software in 2014 and used by companies like Eventbrite, Atlassian, and New Relic to market to more than a billion people. He is an active angel investor, occasional contributor for Slate.com and lives in San Francisco with his wife and young son. He has a BA from Princeton University in English and an MS in Journalism from Northwestern.
Jared Friedman
Managing Director, Software and Group Partner
Jared Friedman is Managing Director, Software and Group Partner at YC. He was cofounder of Scribd, which was funded by Y Combinator in 2006 and grew to be one of the top 100 sites on the web. Jared previously worked at a pioneering AI company and studied computer science at Harvard.
Diana Hu
Group Partner
Diana Hu is a Group Partner at YC. She was co-founder and CTO of Escher Reality (YC S17), an Augmented Reality Backend company that was acquired by Niantic (makers of Pokémon Go). At Niantic, she was the head of the AR platform. Previously, she led data science at OnCue TV that was sold to Verizon. Originally from Chile, Diana graduated from Carnegie Mellon University with a BS and MS in Electrical and Computer Engineering with a focus in computer vision and machine learning.
Surbhi Sarna
Group Partner
Surbhi Sarna is a Group Partner at YC. She was the founder and former CEO of nVision Medical, which developed a first-in-kind microcatheter for the detection of ovarian cancer. After raising $17M in venture funding, completing three clinical trials, and obtaining two first-in-class FDA approvals, nVision was acquired by Boston Scientific (NYSE: BSX) for $275M, more than 15X money-in. Surbhi stayed at Boston Scientific for two years, running the 150+ person commercial organization in preparation for launch. She sits on both private and public company boards.
Michael Seibel
Managing Director, Batch and Group Partner
Michael Seibel is Managing Director, Batch and Group Partner at YC. He was the cofounder and CEO of Justin.tv and Socialcam. Socialcam sold to Autodesk in 2012 and under the leadership of Emmett Shear, Justin.tv became Twitch.tv and sold to Amazon in 2014. Before getting into startups, he spent a year as the finance director for a US Senate campaign and in 2005, Michael graduated from Yale University with a BA in political science.
Harj Taggar
Managing Director and Group Partner
Harj Taggar is a Managing Director and Group Partner at YC. He was previously founder and CEO of Triplebyte (YC S15) and Auctomatic (YC W07), which was acquired by Live Current Media in 2008. He first joined YC as a partner in 2010, leaving in 2014 to start Triplebyte and rejoining in 2020. He graduated in 2006 from Oxford, where he studied Jurisprudence.