About
Mark Feldner worked as a litigator at a major law firm before founding Crimson, which builds AI tools for litigation workflows.
Founder at CrimsonYC X25
Intro paths
YC
Mark 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 David Lieb, General Partner at Y Combinator — the partner who ran Crimson's batch and knows the company first-hand. YC profile ↗
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In turn, Mark can intro founders to Crimson's investors below.
Crimson's investors · 5
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Co-founders at Crimson
DS
David StrömbäckFounder
Experience
- CrimsonCo-Foundercurrent2025 — present
- Willkie Farr & Gallagher LLPAssociate (Dispute Resolution)2021 — 2023Greater London, England, United Kingdom
- WilmerHaleAssociate (Dispute Resolution)2021Greater London, England, United Kingdom
- Clifford ChanceAssociate (Dispute Resolution)2019 — 2021London Area, United Kingdom
- Clifford ChanceTrainee Solicitor2017 — 2019London, United Kingdom
- Cato InstitutePublic Policy Intern2016Washington DC-Baltimore Area
Frequently asked questions
- Who is Mark Feldner?
- Mark Feldner worked as a litigator at a major law firm before founding Crimson, which builds AI tools for litigation workflows.
- Where does Mark Feldner work?
- Mark Feldner is Founder of Crimson.
- What companies did Mark Feldner found?
- Mark Feldner founded Crimson.
- Where did Mark Feldner go to school?
- Mark Feldner studied at University of Cambridge (Bachelor’s Degree, Law); The London School of Economics and Political Science (LSE) (Master’s Degree, Political Theory); BPP Law School (Legal Practice Course, Law).
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
University of Cambridge mafia256
Also came through, then founded or led a company.
Stewart ButterfieldMPhilFounded Flickr +1Demis HassabisBAFounded Google Deepmind +2Immad AkhundMaster of Arts (M.A.)Founded Clickpass +2Inaki BerenguerPhDFounded InfiniteWatch +2Harish AgarwalMaster of Philosophy - MPhilFounded Nori +2Nikola MrkšićDoctor of Philosophy (Ph.D.)Founded Poly +2
+ 249 more
The London School of Economics and Political Science (LSE) mafia133
Also came through, then founded or led a company.
Anne OsdoitCorporate Finance & Strategy - Executive summer schoolFounded Moon Surgical +2Jim McKelveyGeneral CourseFounded Invisibly +1Steve LoughlinCertificateFounded RelateIQ +1James J BesharaDevelopment Economics and International DevelopmentFounded Tilt +1Kyle MichelsonGovernment & GlobalizationFounded Getlabs +1Evan BeardEntrepreneurshipFounded Standard Bots +1
+ 126 more
BPP Law School mafia4
Also came through, then founded or led a company.
Same school
Also attended University of Cambridge1,186
Stewart ButterfieldCo-founder of Slack and FlickrDemis HassabisCo-founder & CEO of Google DeepMindNiko BonatsosVerdict Capital founder and pre-consensus investor formerly at General CatalystGeorgia StevensonInvestor at Index VenturesHannah SealInvestor at Index VenturesLeah von SiemensPartner at Manta Ray Ventures
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+ 1,180 more
Also attended The London School of Economics and Political Science (LSE)1,435
Masayoshi SonFounder, Chairman & CEO of SoftBank GroupLee FixelFounder of AdditionPat GradyPartner at Sequoia CapitalNeil MehtaCo-founder & Managing Partner at GreenoaksCyriac ParisotInvestor at Index VenturesSofia DolfeInvestor at Index Ventures
+ 1,429 more
Shared employers
Also worked at Crimson1
Also worked at Willkie Farr & Gallagher LLP17
Jack LevyInvestor at Israel Cleantech VenturesAmanda NiuGeneral Partner and CFO at Shine CapitalJan Claudio MuñozPartner at Backbone VenturesAndrew EndicottFounding Partner at Gilgamesh VenturesStephen DayManaging Director, Secondaries at Capital DynamicsJohn PakSenior Vice President, Chief Legal Officer at American Century Private Investments
+ 11 more
Also worked at WilmerHale24
André DuboisInvestor at Index VenturesJohn DemeterInvestor at Khosla VenturesBrian GordonManaging Director at Service Provider CapitalCiaran RooneyInvestor at FELIX CAPITALAnmol ChaddhaPrincipal, Programs and Policy at Omidyar NetworkJohn CrandonGeneral Counsel at Thundermark Capital
+ 18 more
Also worked at Clifford Chance47
Jeroen PlinkVenture Partner at LegalTechStephen SwansonChief Legal Officer at Valor Equity PartnersNil GuralPrincipal at Polaris PartnersZi-Yang LimHead of Legal at Jungle VenturesJosé GuardoInvestment & Product Intern at Kibo VenturesVirginia TanFounding & Managing Partner at Teja Ventures
+ 41 more