Fundraising Fox

Geoff Segal

Founder

Co-Founder at FullSeam · Co-Founder at TaxProper

Greater Chicago Area

FoundedFullSeam · YCTaxProper · YC

About

Geoff Segal co-founded TaxProper, a property tax software platform for institutional real estate investors, which was acquired by Opendoor in 2022. He is currently co-founding FullSeam, an AI platform for finance and accounting teams.

Co-Founder at FullSeamYC W26

Intro paths

YC

Geoff went through Y Combinator (Winter 2026) — any YC alum in your network can reach them through the YC community.

GP

Their group partner at YC was Brad Flora, Backing expeditions into the future — the partner who ran FullSeam's batch and knows the company first-hand. YC profile ↗

→

In turn, Geoff can intro founders to FullSeam's investors below.

FullSeam's investors · 1

Y CombinatorSan Francisco · $500K checks · since 2026

Co-founders at FullSeam

TDThomas Dowling
Thomas DowlingCo-founder
ACAaron Coppa
Aaron CoppaCo-founder

Co-Founder at TaxProperYC S19

Intro paths

YC

Geoff went through Y Combinator (Summer 2019) — any YC alum in your network can reach them through the YC community.

→

In turn, Geoff can intro founders to TaxProper's investors below.

TaxProper's investors · 5

Cathexis VenturesHouston · $250K – $1M checksClocktower VenturesSanta Monica · $100K – $20M checksEra VenturesNew YorkKhosla VenturesMenlo Park · $5K – $50M checksY CombinatorSan Francisco · $500K checks · since 2019

Co-founders at TaxProper

TDThomas Dowling
Thomas DowlingCo-founder

Experience

  1. FullSeamCo-Foundercurrent2025 — present
  2. OpendoorDirector, TaxProper2022 — 2025
  3. TaxProperCo-Founder2019 — 2022Greater Chicago Area
  4. State Farm ®Data Science & Actuarial2015 — 2019Bloomington, Illinois

Frequently asked questions

Who is Geoff Segal?
Geoff Segal co-founded TaxProper, a property tax software platform for institutional real estate investors, which was acquired by Opendoor in 2022. He is currently co-founding FullSeam, an AI platform for finance and accounting teams.
Where does Geoff Segal work?
Geoff Segal is Co-Founder of FullSeam and Co-Founder at TaxProper.
What companies did Geoff Segal found?
Geoff Segal founded FullSeam, TaxProper.
Where did Geoff Segal go to school?
Geoff Segal studied at University of Illinois Urbana-Champaign (Master of Science - MS, Statistics); University of Illinois Urbana-Champaign (Bachelor’s Degree, Statistics and Economics); Y Combinator (S19).

Founder mafias

Y Combinator mafia8,773

Also came through, then founded or led a company.

Sam AltmanPresidentFounded Tools for Humanity +3Jessica LivingstonCo-founderFounded Y CombinatorAlexis OhanianYC Summer 2005Founded RedditFred EhrsamYC Summer 2012Founded Nudge +1Matt HuangYC Winter 2011Founded HotspotsTrae StephensYC Winter 2022Founded Pursuit +1

+ 8,766 more

Y Combinator mafia4,716

Also came through, then founded or led a company.

Ryan SheaEntrepreneurshipFounded StacksTarek MansourFounded KalshiSuhail DoshiEating beans & riceFounded Playground +1Subomi OluwalanaW22Founded ConvoyDarius "Bubs" MonsefS19Founded Sightbox +3Matthew ScholzFounded Oisin Biotechnologies +3

+ 4,709 more

University of Illinois Urbana-Champaign mafia146

Also came through, then founded or led a company.

Max LevchinBSFounded PayPal +1Luke NosekBSFounded PayPalAnsuman SatpathyPhilosophyFounded Santa Ana Bio +2DeVaris BrownB.S.Founded Super Heroic +2Harish AgarwalB.S.Founded Nori +2Amitt MahajanBSFounded Rare Bits +1

+ 139 more

TaxProper mafia3

Also came through, then founded or led a company.

Thomas DowlingCo-founderFounded FullSeamAaron CoppaHead of ProductFounded FullSeam

FullSeam mafia2

Also came through, then founded or led a company.

Thomas DowlingCo-founderFounded TaxProper

Same school

Also attended University of Illinois Urbana-Champaign489

Max LevchinCo-founder of PayPal; founder, chairman & CEO of Affirm; partner at SciFi VCLuke NosekCo-founder of PayPal; co-founder of GigafundSundeep PeechuGeneral Partner at Felicis VenturesDeep NisharInvestment Team at General CatalystPrashant ShahPartner at Monta Vista CapitalNoorPartner at Clear Ventures

+ 483 more

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 VenturesMaroof AhmedFounder at Octopus VenturesJustin SwartPartner at Bitkraft Esports Ventures

+ 1,994 more

Shared employers

Also worked at FullSeam1

Aaron CoppaCo-founder at FullSeam

Also worked at Opendoor41

Darcy YeeMarketing and Communications at Menlo VenturesGlenn SolomonInvestor at GGV CapitalJon ChuInvestor at Khosla VenturesBrett BrowmanInvestor at Khosla VenturesMatt MocharyInvestor at Fortius VenturesIan J. NicholsonOperating Partner at Advent Life Sciences

+ 35 more

Also worked at TaxProper3

Donald StalterPartner at Sunshine LakeThomas TarnowskiManaging Director at Summit PartnersAaron CoppaCo-founder at FullSeam

Also worked at State Farm ®16

Matt AdamczykTechnologist in Residence at TitletownTechEdmundo PichardoOffice Manager at SpeedinvestHan LeePhysical AI Fellow at ClimacticChristopher O'DoreSenior Associate at Advance Venture PartnersDevin WingfieldInvestor at High Street Equity PartnersNikki OrthDirector of Operations & Finance at 2Flo Ventures

+ 10 more