Firms
Irregular Expressions
New York, United States · San Francisco, United States
Irregular Expressions (IrregEx) is an early-stage venture investment platform based in New York and San Francisco, backing business-to-developer infrastructure software at pre-seed and seed. Its published focus includes artificial intelligence, data engineering, DevOps, security, observability and developer productivity. Founder and General Partner Jean Sini began an engineering-leader syndicate in 2018 and converted it into a venture fund in 2022. Its portfolio distinguishes Fund I investments from earlier SPV investments. The current public directory lists 99 people: Jean Sini, Principal Vlad Rachev and a community of advisors and limited partners drawn from engineering and product leadership; these community affiliations do not imply 99 salaried employees or general partners. No primary-source fund closing amount or current AUM was verified. IrregEx is distinct from the AI-security company Irregular at irregular.com.
- Founded
- 2018
- Type
- Venture capital
Funds1
Team
 Jean Sini Irregular Expressions, Founder and General Partner | $8M$100K – $12M | New York, New York |
Operations and support
 Achin BatraAdvisor / Limited partner (published directory affiliation) |
 Adam BilderseeAdvisor / Limited partner (published directory affiliation) |
 Adam PerelmanAdvisor / Limited partner (published directory affiliation) |
 Alan WarrenAdvisor / Limited partner (published directory affiliation) |
 Alex IngramAdvisor / Limited partner (published directory affiliation) |
 Alexandre AttiaAdvisor / Limited partner (published directory affiliation) |
 Alexandre WinterAdvisor / Limited partner (published directory affiliation) |
 Alexis Lê-QuôcAdvisor / Limited partner (published directory affiliation) |
 Ali HeronAdvisor / Limited partner (published directory affiliation) |
 Andrew BunnerAdvisor / Limited partner (published directory affiliation) |
 Andrew HogueAdvisor / Limited partner (published directory affiliation) |
 Andrey AkselrodAdvisor / Limited partner (published directory affiliation) |
 Anthony JohnsonAdvisor / Limited partner (published directory affiliation) |
 Antoine BoulangerAdvisor / Limited partner (published directory affiliation) |
 Ariana PoursartipAdvisor / Limited partner (published directory affiliation) |
 Arun NagarajanAdvisor / Limited partner (published directory affiliation) |
 Ashley MillerAdvisor / Limited partner (published directory affiliation) |
 Ben BirnbaumAdvisor / Limited partner (published directory affiliation) |
 Ben RobertsAdvisor / Limited partner (published directory affiliation) |
 Benjamin FabreAdvisor / Limited partner (published directory affiliation) |
 Brian MurphyAdvisor / Limited partner (published directory affiliation) |
 Bryan MahoneyAdvisor / Limited partner (published directory affiliation) |
 Camille FournierAdvisor / Limited partner (published directory affiliation) |
 Carlos AguilarAdvisor / Limited partner (published directory affiliation) |
 Carter PerezAdvisor / Limited partner (published directory affiliation) |
 Chris CraneAdvisor / Limited partner (published directory affiliation) |
 Cyril DerembleAdvisor / Limited partner (published directory affiliation) |
 Dan PrestonAdvisor / Limited partner (published directory affiliation) |
 Danny MorrowAdvisor / Limited partner (published directory affiliation) |
 David AndreAdvisor / Limited partner (published directory affiliation) |
 Doug BemisAdvisor / Limited partner (published directory affiliation) |
 Elijah MeersonAdvisor / Limited partner (published directory affiliation) |
 Fazal YameenAdvisor / Limited partner (published directory affiliation) |
 Geoff CalkinsAdvisor / Limited partner (published directory affiliation) |
 Gil ShklarskiAdvisor / Limited partner (published directory affiliation) |
 Greg RatnerAdvisor / Limited partner (published directory affiliation) |
 Hrishi DixitAdvisor / Limited partner (published directory affiliation) |
 Ilan ManAdvisor / Limited partner (published directory affiliation) |
 Ilia PapasAdvisor / Limited partner (published directory affiliation) |
 Irina KrechmerAdvisor / Limited partner (published directory affiliation) |
 James BoehmerAdvisor / Limited partner (published directory affiliation) |
 James PsotaAdvisor / Limited partner (published directory affiliation) |
 James TurnbullAdvisor / Limited partner (published directory affiliation) |
 Jay SignorelloAdvisor / Limited partner (published directory affiliation) |
 Joel WittenAdvisor / Limited partner (published directory affiliation) |
 Jonah CohenAdvisor / Limited partner (published directory affiliation) |
 Julie HubschmanAdvisor / Limited partner (published directory affiliation) |
 Julie SommervilleAdvisor / Limited partner (published directory affiliation) |
 Junaid AhmedAdvisor / Limited partner (published directory affiliation) |
 Jurica CerovecAdvisor / Limited partner (published directory affiliation) |
 Katelyn LesseAdvisor / Limited partner (published directory affiliation) |
 Kathleen YanolatosAdvisor / Limited partner (published directory affiliation) |
 Kellan Elliott-McCreaAdvisor / Limited partner (published directory affiliation) |
 Kurt SchraderAdvisor / Limited partner (published directory affiliation) |
 Laura FlorescuAdvisor / Limited partner (published directory affiliation) |
 Laurent ParisAdvisor / Limited partner (published directory affiliation) |
 Leonid IgolnikAdvisor / Limited partner (published directory affiliation) |
 Liz MaidaAdvisor / Limited partner (published directory affiliation) |
 Mackenzie KosutAdvisor / Limited partner (published directory affiliation) |
 Marc BrownAdvisor / Limited partner (published directory affiliation) |
 Marc MeyerAdvisor / Limited partner (published directory affiliation) |
 Marcus FrödinAdvisor / Limited partner (published directory affiliation) |
 Maria BelousovaAdvisor / Limited partner (published directory affiliation) |
 Matt DriscollAdvisor / Limited partner (published directory affiliation) |
 Matthew DrookerAdvisor / Limited partner (published directory affiliation) |
 Michael CoyneAdvisor / Limited partner (published directory affiliation) |
 Michele CatastaAdvisor / Limited partner (published directory affiliation) |
 Mike BouffordAdvisor / Limited partner (published directory affiliation) |
 Mike ReustAdvisor / Limited partner (published directory affiliation) |
 Mircea PasoiAdvisor / Limited partner (published directory affiliation) |
 Nate WigerAdvisor / Limited partner (published directory affiliation) |
 Nick RockwellAdvisor / Limited partner (published directory affiliation) |
 Oliver PlattnerAdvisor / Limited partner (published directory affiliation) |
 Ori SchnapsAdvisor / Limited partner (published directory affiliation) |
 Pablo MendesAdvisor / Limited partner (published directory affiliation) |
 Peter BellAdvisor / Limited partner (published directory affiliation) |
 Rachana KumarAdvisor / Limited partner (published directory affiliation) |
 Renaud VisageAdvisor / Limited partner (published directory affiliation) |
 Robyn PetersonAdvisor / Limited partner (published directory affiliation) |
 Romain DavidAdvisor / Limited partner (published directory affiliation) |
 Sam MooreAdvisor / Limited partner (published directory affiliation) |
 Sameer JainAdvisor / Limited partner (published directory affiliation) |
 Samuel RozenbergAdvisor / Limited partner (published directory affiliation) |
 Scott BreitenotherAdvisor / Limited partner (published directory affiliation) |
 Serkan KutanAdvisor / Limited partner (published directory affiliation) |
 Sheba RassonAdvisor / Limited partner (published directory affiliation) |
 Steven KuyanAdvisor / Limited partner (published directory affiliation) |
 Supreet OberoiAdvisor / Limited partner (published directory affiliation) |
 Swaroop ButalaAdvisor / Limited partner (published directory affiliation) |
 Sylvia IslerAdvisor / Limited partner (published directory affiliation) |
 Taylor LeeseAdvisor / Limited partner (published directory affiliation) |
 Tejpaul BhatiaAdvisor / Limited partner (published directory affiliation) |
 Theresa VuAdvisor / Limited partner (published directory affiliation) |
 Varun SrinivasanAdvisor / Limited partner (published directory affiliation) |
 Vlad RachevPrincipal |
 Yony FengAdvisor / Limited partner (published directory affiliation) |
 Zach AbramsAdvisor / Limited partner (published directory affiliation) |
 Zachary OzerAdvisor / Limited partner (published directory affiliation) |
Co-investing
Y Combinator
Weave AI Coding$13M · 2026-07-28
Lemma$2M · 2026
Salt$3M · 2024
Agent Fund- Weave AI Coding$13M · 2026-07-28
Anorak Ventures
Mermaid$7M · 2024
Burst Capital
- Weave AI Coding$13M · 2026-07-28
Flashpoint
- Mermaid$7M · 2024
Liquid 2 Ventures
- Lemma$2M · 2026
Matrix Partners
- Lemma$2M · 2026
Moonfire Ventures- Weave AI Coding$13M · 2026-07-28
Morpheus Ventures
- Salt$3M · 2024
Partech Africa
Pydantic$12M · 2024-10-01
Position Ventures- Lemma$2M · 2026
Standard Capital- Weave AI Coding$13M · 2026-07-28
Streamlined Ventures
- Mermaid$7M · 2024
Struck Capital
- Salt$3M · 2024
Investments
| $13M2026-07-28 | Weave AI Coding | Standard Capital, Y Combinator, Burst Capital, Agent Fund, Moonfire Ventures, Irregular Expressions |
| $2M2026 | Lemma | Y Combinator, Liquid 2 Ventures, Position Ventures, Matrix Partners, Cervin, Irregular Expressions |
| $12M2024-10-01 | Pydantic | Sequoia, Partech Africa, Irregular Expressions, Partech |
| $3M2024 | Salt | Y Combinator, Struck Capital, Morpheus Ventures, Irregular Expressions |
| $7M2024 | Mermaid | Sequoia, Anorak Ventures, Streamlined Ventures, Gaingels, Irregular Expressions, Flashpoint |
| $—Unknown date |  Tsuga | Irregular Expressions |
| $—Unknown date |  TopK | Irregular Expressions |
| $—Unknown date |  Recall | Irregular Expressions |
| $—Unknown date |  Qovery | Irregular Expressions |
| $—Unknown date |  Play | Irregular Expressions |
| $—Unknown date |  Inventive | Irregular Expressions |
| $—Unknown date |  Escape | Irregular Expressions |
| $—Unknown date |  Anchor | Irregular Expressions |
| $—Unknown date |  Alpic | Irregular Expressions |