Fundraising Fox

Allan Guo

Founder

Founder at Willow

United States

FoundedWillow · YC

Find your path to Allan

464 people in our graph share verified history with Allan — schools, employers, funds. One of them is your warm intro.

Garry TanunlockedAllan: together at Y Combinator (2024)
×11Allan: together at Y Combinator

About

Allan Guo studied computer science at Stanford and conducted research in machine learning and neuroscience at Stanford Medical School. He co-founded and leads Willow, and has previously worked on ventures in music, healthcare technology, and e-commerce.

Founder at WillowYC X25

Intro paths

YC

Allan went through Y Combinator (Spring 2025) — any YC alum in your network can reach them through the YC community.

GP

Their group partner at YC was Nicolas Dessaigne, General Partner at Y Combinator — the partner who ran Willow's batch and knows the company first-hand. YC profile ↗

→

In turn, Allan can intro founders to Willow's investors below.

Willow's investors · 2

Hetz VenturesTel Aviv · $3.6M – $90M checksY CombinatorSan Francisco · $500K checks · since 2025

Experience

  1. WillowCo-founder & CEOcurrent2025 — presentSan Francisco, California, United States
  2. Willow (Healthcare)Co-founder & CEO2024 — 2025San Francisco Bay Area
  3. Stanford University School of MedicineML Research2022 — 2023

Frequently asked questions

Who is Allan Guo?
Allan Guo studied computer science at Stanford and conducted research in machine learning and neuroscience at Stanford Medical School. He co-founded and leads Willow, and has previously worked on ventures in music, healthcare technology, and e-commerce.
Where does Allan Guo work?
Allan Guo is Founder of Willow.
What companies did Allan Guo found?
Allan Guo founded Willow.
Where did Allan Guo go to school?
Allan Guo studied at Y Combinator; Stanford University (Bachelor's degree, Computer Science); University of Toronto Schools (High school).

Founder mafias

Y Combinator mafia10,230

Also came through, then founded or led a company.

Sam AltmanPresidentFounded Tools for Humanity +3Garry TanPresident & CEOFounded Y Combinator +1Jessica LivingstonCo-founderFounded Y CombinatorAlexis OhanianPartnerFounded RedditFred EhrsamYC Summer 2012Founded Nudge +1Matt HuangYC Winter 2011Founded Paradigm +1

+ 10,223 more

Stanford University mafia1,934

Also came through, then founded or led a company.

Peter ThielB.A.Founded PayPalReid HoffmanB.S.Founded LinkedIn +2David SacksB.A.Founded YammerKeith RaboisB.A.Founded OpendoorGarry TanBSFounded Y Combinator +1Joe LonsdaleBSFounded Opto +5

+ 1,927 more

University of Toronto Schools mafia13

Also came through, then founded or led a company.

Kiva DickinsonFounded CadootzAli JiwaniFounded RallyCydney KimFounded Fortuna HealthJeff AnHigh SchoolFounded MomenticJason ZhouFounded SwerveAshley MoFounded Liva AI

+ 6 more

Same school

Also attended Y Combinator2,000

Tarek MansourCo-founder & CEO of KalshiSuhail DoshiFounder of Mixpanel; founder of ParticleSubomi OluwalanaCo-founder & CEO of ConvoyArhaan A.Deeptech Fellow at Clear VenturesCollin WallaceGeneral Partner at Lobby CapitalVictor SantosVictor Scout at One Way Ventures

+ 1,994 more

Also attended Stanford University2,000

Peter ThielCo-founder & Partner at Founders FundDavid SacksCo-founder & General Partner at Craft Ventures; former White House AI & Crypto CzarGarry TanPresident & CEO of Y CombinatorAlfred LinPartner at Sequoia CapitalJim BreyerFounder & CEO of Breyer CapitalMike Maples JrCo-founding Partner at Floodgate

+ 1,994 more

Also attended University of Toronto Schools26

John GreenwoodPartner at Pantheon VenturesSimu LiuCo-Founder at MARKHAM VALLEY VENTURESSarah LiuPartner at Fifth WallNick ChenPrincipal at Golden VenturesKiva DickinsonManaging Partner at Selva VenturesFraser StarkHead of Portfolio Solutions & Strategy at Purpose Investments

+ 20 more

Shared employers

Also worked at Stanford University School of Medicine205

Josephine ChenInvestor at Sequoia CapitalJeffrey FinerVenture Partner at Third Rock VenturesFrancisco GimenezInvestment Team at 8VCLan JiangPartner at Lux CapitalJeffrey DeFlavio, MDEntrepreneur in Residence at AlleyCorpLily RaakaStrategist at Plum Alley Investments

+ 199 more