What Companies Were in Y Combinator S25?
The Y Combinator Summer 2025 (S25) batch included startups building across AI, developer tools, healthcare, fintech, robotics, enterprise software, cybersecurity, defense, biotech, productivity, and other emerging categories — including Vulcan Technologies, Luminal, VibeFlow, TectoAI, Reacher, Nox Metals, RealRoots, Magnetic, Uplift AI, Humoniq, Interfere, Blank Bio, IronLedger, Albacore, Perseus Defense, Avelis Health, AgentMail, Cactus Compute, Mastra, Fyxer AI, Cluely, and many others.
Y Combinator S25 at a Glance
| Accelerator | Y Combinator |
| Batch | Summer 2025 (S25) |
| Year | 2025 |
| Companies covered | 199 |
| Industries represented | AI, developer tools, healthcare, fintech, robotics, cybersecurity, defense, enterprise software and more |
| Company signals | Accelerator participation, funding, hiring, launches, adoption and growth |
| Primary use | Startup discovery and lead generation |
What companies were in the Y Combinator S25 batch?
Y Combinator S25 included startups across AI infrastructure, developer tools, healthcare, fintech, robotics, defense, cybersecurity, enterprise software, consumer technology, productivity, real estate, biotech, and other emerging categories.
| # | Company | Industry / Category |
|---|---|---|
| 1 | Vulcan Technologies | GovTech / Legal & Compliance |
| 2 | Luminal | AI Infrastructure & Developer Tools |
| 3 | VibeFlow | B2B Productivity & Developer Tools |
| 4 | TectoAI | AI Governance & Compliance |
| 5 | Reacher | MarTech / Creator Economy |
| 6 | Nox Metals | Industrial & Manufacturing |
| 7 | RealRoots | Consumer / Social Network |
| 8 | Magnetic | FinTech / AI Tax Automation |
| 9 | Uplift AI | AI Voice Infrastructure |
| 10 | Humoniq | Travel / Conversational AI |
| 11 | Interfere | B2B SaaS |
| 12 | Blank Bio | Healthcare / Biotech |
| 13 | IronLedger | Real Estate Finance |
| 14 | BootLoop | B2B Engineering |
| 15 | EffiGov | GovTech |
| 16 | truthsystems | B2B Infrastructure |
| 17 | Kalinda | Legal Tech |
| 18 | Sira | HR Tech |
| 19 | Mobile Operator | Software Development |
| 20 | Bitrig | Developer Tools |
| 21 | Blue | Consumer Electronics |
| 22 | Pingo | EdTech |
| 23 | Albacore | Defense |
| 24 | Perseus Defense | Defense |
| 25 | Juxta | IoT / GovTech |
| 26 | Nexa Labs | Agriculture / Hardware |
| 27 | Ambral | SaaS |
| 28 | April | Productivity Software |
| 29 | Altur | FinTech |
| 30 | Lark | B2B SaaS |
| 31 | Epicenter | Productivity Software |
| 32 | Pally | B2B Productivity |
| 33 | Avelis Health | Healthcare AI |
| 34 | Paloma | Enterprise Software |
| 35 | Phases | Healthcare AI |
| 36 | Parachute | Healthcare IT |
| 37 | Novaflow | Healthcare |
| 38 | Perspectives Health | Healthcare IT |
| 39 | Dedalus Labs | Developer Tools |
| 40 | Evergrove Labs | Healthcare IT |
| 41 | Pharmie AI | Healthcare / Pharmacy |
| 42 | Fluidize | B2B Infrastructure |
| 43 | Closera | B2B E-commerce |
| 44 | Candytrail | Sales Tech |
| 45 | Finto | FinTech |
| 46 | Alara | Healthcare IT |
| 47 | AgentMail | Software |
| 48 | Flywheel AI | Robotics |
| 49 | Alter AI | AI Security |
| 50 | Cactus Compute | Developer Tools |
| 51 | Orange Slice | Sales Tech |
| 52 | TraceRoot | Developer Tools |
| 53 | Modelence | Developer Tools |
| 54 | Solva Technology | InsurTech |
| 55 | Meteor | Consumer Software |
| 56 | Clodo | B2B SaaS |
| 57 | Nuntius | B2B Infrastructure |
| 58 | ZeroEval | Developer Tools |
| 59 | Planisphere | PropTech |
| 60 | Minimal AI | B2B SaaS |
| 61 | Kernel | B2B SaaS |
| 62 | Normal Factory | Defense Technology |
| 63 | Verne Robotics | Robotics |
| 64 | Material Model | Frontier Tech |
| 65 | Duranium | Frontier Tech |
| 66 | Astor | Consumer Finance |
| 67 | Fulcrum | Developer Tools |
| 68 | Veritus Agent | Finance / SaaS |
| 69 | Stormy AI | AI / Marketing |
| 70 | CareSwift | Healthcare AI |
| 71 | Wisp AI | Productivity SaaS |
| 72 | Hera | Consumer AI |
| 73 | Summon | Developer Tools |
| 74 | Cyberdesk | AI Infrastructure |
| 75 | Careflick | Healthcare AI |
| 76 | Manufact | Cloud Infrastructure |
| 77 | Autumn | Enterprise Software |
| 78 | Spotlight Realty | Real Estate Tech |
| 79 | Keystone | Developer Tools |
| 80 | Mimos | Not specified |
| 81 | Acrely | AI / Local Services |
| 82 | Wayline | Real Estate Tech |
| 83 | GetASAP | Logistics / Distribution |
| 84 | Preseen | AI / Data Analytics |
| 85 | Rid | Consumer / E-commerce |
| 86 | Slashy | B2B Software |
| 87 | Twill.ai | Developer Tools |
| 88 | Risely | EdTech |
| 89 | Omnara | Developer Tools |
| 90 | Hyprnote | Electrical Manufacturing |
| 91 | Channel3 | Software |
| 92 | Nia | Developer Tools |
| 93 | Golpo | Video Software |
| 94 | Opennote | EdTech |
| 95 | Inversion Semiconductor | Semiconductors |
| 96 | WorkDone | Healthcare IT |
| 97 | Rimba | Enterprise Software |
| 98 | Clarm | Enterprise Software |
| 99 | Probo | Enterprise Software |
| 100 | Crimson | LegalTech |
| 101 | Third Chair | LegalTech |
| 102 | Vesence | LegalTech |
| 103 | The Robot Learning Company | Robotics |
| 104 | Almond | Robotics |
| 105 | Vassar Robotics | Robotics |
| 106 | MorphoAI | Robotics |
| 107 | Zeon Systems | Robotics |
| 108 | Mbodi AI | Robotics |
| 109 | Jazzberry | Developer Tools |
| 110 | Bloom | Developer Tools |
| 111 | Vybe | Developer Tools |
| 112 | Waffle | Developer Tools |
| 113 | Shor | FinTech / HR |
| 114 | Maximal | Logistics Software |
| 115 | Palace | Software |
| 116 | Stagewise | Developer Tools |
| 117 | Mastra | Developer Tools |
| 118 | Aegis Health, Inc. | Healthcare IT |
| 119 | Moss | Enterprise Software |
| 120 | Perfectly | HRTech |
| 121 | Kyten Technologies | Aerospace / Manufacturing |
| 122 | MochaTrade | FinTech |
| 123 | Cofia | Enterprise Software |
| 124 | Nessie | Productivity Software |
| 125 | Cell Type | Biotech |
| 126 | Polymorph | Enterprise Software |
| 127 | Sparkles | Developer Tools |
| 128 | Photonium | DeepTech |
| 129 | BitPatrol | Cybersecurity |
| 130 | Casco | Cybersecurity |
| 131 | Mindfort | Cybersecurity |
| 132 | Cotool | Cybersecurity |
| 133 | Halluminate | Developer Tools |
| 134 | Design Arena | Design / Developer Tools |
| 135 | Naive | AI Software |
| 136 | Fyxer AI | AI Assistants |
| 137 | SRE.ai | DevOps |
| 138 | OnboardFlow AI | Marketing Tech |
| 139 | Blueheyblue (Blue) | Mobile Apps |
| 140 | Idler | AI Infrastructure |
| 141 | Nixo | AI Infrastructure |
| 142 | Munify | Financial Services |
| 143 | NOSO LABS | B2B SaaS |
| 144 | Parachute (Conviction) | FinTech |
| 145 | Lilac | AI Platform |
| 146 | Normal | Compliance Software |
| 147 | Truth Systems | Compliance / Cybersecurity |
| 148 | Solva | Enterprise Software |
| 149 | Pingo AI | Consumer App / Education |
| 150 | Pickle | Software |
| 151 | mlop | B2B SaaS / Developer Tools |
| 152 | Tensr | Robotics Software |
| 153 | Cleon | Enterprise Software |
| 154 | Mocha Care | Healthcare Tech / B2B SaaS |
| 155 | Claim Health | Healthcare Tech |
| 156 | Efference | Robotics / Computer Vision |
| 157 | Sidekick | Enterprise Software |
| 158 | TamLabs | Enterprise Software |
| 159 | Nimbic AI | Developer Tools |
| 160 | Floot | No-Code Software |
| 161 | Martin | Productivity Software |
| 162 | Dex | B2B Recruiting |
| 163 | Cluely | B2B Sales |
| 164 | Datafruit | DevOps |
| 165 | Proliferate | Developer Tools |
| 166 | Tecto | HR Tech |
| 167 | PARES AI | PropTech / AI |
| 168 | ContextFort | PropTech |
| 169 | Embedder | Embedded Software / AI |
| 170 | Openmart | Data Intelligence |
| 171 | Ghostship | Developer Tools / AI |
| 172 | Fleetline | Logistics / AI |
| 173 | Socratix AI | FinTech / AI |
| 174 | Mayflower | HR Tech / Compliance |
| 175 | RealPact | PropTech / AI |
| 176 | Beacon | PropTech |
| 177 | Cactus | AI Infrastructure |
| 178 | Salus | Infrastructure |
| 179 | Understudy | Infrastructure |
| 180 | Riften | Infrastructure |
| 181 | Traversal | Developer Tools |
| 182 | Superlog | Developer Tools |
| 183 | Wedge | Healthcare Tech |
| 184 | Prism | Analytics Software |
| 185 | Plexe | AI Developer Tools |
| 186 | Alter | Cybersecurity |
| 187 | LegalScribe AI | LegalTech |
| 188 | Comena | Supply Chain |
| 189 | Tesora | Procurement / AI |
| 190 | burnt | Supply Chain |
| 191 | Parametric | Robotics |
| 192 | Iron Grid | InsurTech / AI |
| 193 | MangoDesk | HealthTech |
| 194 | Lakonia | GovTech / Defense |
| 195 | Mendral | DevOps |
| 196 | Freya | Voice AI |
| 197 | Flywheel | Construction Tech |
| 198 | Riff | Media / AI |
| 199 | Doe | Software |
Y Combinator S25 company profiles
Vulcan Technologies
GovTech / Legal & Compliance · Austin, Texas · Y Combinator S25
Vulcan Technologies is an Austin-based GovTech company founded in 2025. The company builds technology across government, legal, and compliance workflows. By July 2026, Vulcan Technologies had raised $11 million across one funding round and grown to a 17-person team. It was also recruiting across technical and commercial roles, including an SDR/BDR role and a Security Engineer.
Post-batch signal: Funding + hiring
Luminal
AI Infrastructure & Developer Tools · San Francisco, California · Y Combinator S25
Luminal is an AI infrastructure and developer-tools company founded in 2025 by Joe Fioti, Matthew Gunton, and Jake Stevens. The San Francisco company grew to a seven-person team and was recruiting for specialized technical roles including Cloud Inference Engineer and Compiler Engineer, with listed salary ranges reaching $250,000.
Post-batch signal: Hiring
VibeFlow
B2B Productivity & Developer Tools · San Francisco, California · Y Combinator S25
VibeFlow is a San Francisco developer-tools company founded in 2025 by Alessia Paccagnella and Elia Saquand. The company builds a web application generator and received $500,000 in pre-seed funding from Y Combinator. VibeFlow publicly launched its platform on Hacker News on September 21, 2025, where the launch received 103 points and 55 comments.
Post-batch signal: Funding + product launch
TectoAI
AI Governance & Compliance · San Francisco, California · Y Combinator S25
TectoAI is an AI governance and compliance company founded by Niosha Afsharikia and Roksana Baleshzar in San Francisco. TectoAI presented during Y Combinator Demo Day in September 2025. The company focuses on technology for governing and managing AI systems.
Reacher
MarTech / Creator Economy · San Francisco, California · Y Combinator S25
Reacher is a San Francisco MarTech company founded in 2024 by Bora Mutluoglu and Jerry Qian. Reacher received $500,000 in YC funding and subsequently grew to a 10-person team. By early 2026, the company was actively recruiting across five roles.
Post-batch signal: Funding + hiring
Nox Metals
Industrial & Manufacturing · Detroit, Michigan · Y Combinator S25
Nox Metals is a Detroit-based industrial and manufacturing company founded in 2025 by Zane Hengsperger. Nox Metals presented during Y Combinator Demo Day in September 2025. The company reached a team of 35 employees and later recruited for a Sales/Growth/GTM Lead, with a listed salary range of $100,000 to $250,000.
Post-batch signal: Team growth + hiring
Magnetic
FinTech / AI Tax Automation · San Francisco, California · Y Combinator S25
Magnetic is a fintech company founded in 2024 by Thomas Shelley and Patrick Fay that applies AI and software to tax workflows. Magnetic launched during the 2025 tax season and processed hundreds of returns. By early 2026, the company was also recruiting across multiple roles.
Post-batch signal: Adoption + hiring
Uplift AI
AI Voice Infrastructure · San Francisco, California · Y Combinator S25
Uplift AI is a voice AI infrastructure company founded in 2025 by Hammad Malik, Zaid Qureshi, and Muhammad Bin Sabir. The three-person company publicly launched its Orator Urdu voice model in August 2025, placing Uplift AI within the voice and language AI segment of S25.
Post-batch signal: Product launch
Humoniq
Travel / Conversational AI · San Francisco, California · Y Combinator S25
Humoniq is a conversational AI company founded in 2025 by Todd Sullivan and Will Weber. The five-person San Francisco company launched an AI contact center for travel in August 2025, applying conversational AI to customer-service workflows in the travel industry.
Post-batch signal: Product launch
Interfere
B2B SaaS · New York City, New York · Y Combinator S25
Interfere is a New York City B2B software company. The company raised $5.1 million in 2025 from investors including Y Combinator, Vercel Ventures, Hummingbird, and Designer Fund. Interfere also expanded its eight-person New York team and opened a Strategy & Operations position.
Post-batch signal: Funding + hiring
Albacore
Defense · Philadelphia, Pennsylvania · Y Combinator S25
Albacore is a Philadelphia-based defense technology company founded in 2025. Albacore raised a $6.5 million seed round in October 2025, led by Outlander VC. The company also scheduled a Department of Defense demonstration for January 2026.
Post-batch signal: Funding + government traction
Perseus Defense
Defense · San Francisco, California · Y Combinator S25
Perseus Defense is a San Francisco defense technology company developing low-cost micro-missile systems. The company raised a $6 million seed round in September 2025 from 15 investors, including Alumni Ventures and Bow Capital. Its micro-missiles were priced at under $5,000 per unit.
Post-batch signal: Funding
Pingo
EdTech · San Francisco, California · Y Combinator S25
Pingo is a San Francisco education technology company founded in 2025. By July 2025, Pingo had reached 300,000 users and $200,000 in monthly recurring revenue, alongside 100% month-over-month growth.
Post-batch signal: User + revenue growth
Dedalus Labs
Developer Tools · San Francisco, California · Y Combinator S25
Dedalus Labs is a San Francisco developer-tools company. In October 2025, Dedalus Labs raised $11 million in seed funding, led by Kindred Ventures and Saga Ventures.
Post-batch signal: Funding
Pharmie AI
Healthcare / Pharmacy · San Francisco, California · Y Combinator S25
Pharmie AI is a healthcare technology company founded in 2025 that applies AI to pharmacy workflows. By August 2025, Pharmie AI's technology was handling up to 70% of phone calls autonomously for multiple pharmacies, providing a concrete adoption signal within healthcare operations.
Post-batch signal: Adoption
Orange Slice
Sales Tech · San Francisco, California · Y Combinator S25
Orange Slice is a San Francisco sales technology company founded in 2025. The company raised $5.3 million in seed funding and reached more than 5,000 sales and RevOps teams. Orange Slice was also recruiting for a Founding Engineer.
Post-batch signal: Funding + customer growth
Cactus Compute
Developer Tools · San Francisco, California · Y Combinator S25
Cactus Compute is a San Francisco developer-tools company founded in 2025. The company grew to an eight-person team and hosted a Mobile Agent Hackathon in November 2025, reflecting its focus on the emerging AI-agent developer ecosystem.
Post-batch signal: Team growth + ecosystem activity
What industries were most common in Y Combinator S25?
AI and AI-enabled software were prominent across Y Combinator S25, appearing in developer tools, healthcare, enterprise software, robotics, cybersecurity, sales, finance, productivity, and other categories.
| Category | Example S25 companies |
|---|---|
| AI infrastructure & developer tools | Luminal, Cactus Compute, TraceRoot, ZeroEval, Cyberdesk, Idler, Nixo, Plexe |
| Healthcare & healthcare AI | Avelis Health, Phases, Novaflow, CareSwift, Careflick, Mocha Care, Claim Health |
| Enterprise & B2B software | Paloma, Clodo, Minimal AI, Kernel, Rimba, Probo, Polymorph |
| Robotics & physical AI | Flywheel AI, Verne Robotics, The Robot Learning Company, Vassar Robotics, MorphoAI, Mbodi AI |
| FinTech | Magnetic, Altur, Finto, Astor, MochaTrade, Munify, Socratix AI |
| Cybersecurity | Alter AI, BitPatrol, Casco, Mindfort, Cotool |
| Defense & frontier technology | Albacore, Perseus Defense, Normal Factory, Duranium, Lakonia |
| Sales & marketing technology | Reacher, Candytrail, Orange Slice, Stormy AI, Cluely |
| Legal & compliance | Vulcan Technologies, TectoAI, Kalinda, Crimson, Third Chair, Vesence |
| PropTech | Planisphere, Spotlight Realty, Wayline, PARES AI, ContextFort, RealPact |
A defining characteristic of S25 is that AI appears across specific industries and workflows rather than functioning only as a standalone category.
Which Y Combinator S25 companies are building AI developer tools?
Luminal, Cactus Compute, TraceRoot, Modelence, ZeroEval, Fulcrum, Summon, Keystone, Omnara, Jazzberry, Bloom, Stagewise, Mastra, Sparkles, Halluminate, SRE.ai, Nimbic AI, Proliferate, Traversal, Superlog, and Plexe are among the S25 companies building developer tools or AI infrastructure.
Their technologies span AI inference, development environments, observability, evaluation, DevOps, application development, agent tooling, and infrastructure for deploying AI systems. Developer infrastructure was one of the clearest technical themes represented across S25.
Which YC S25 companies are building healthcare technology?
Avelis Health, Phases, Parachute, Novaflow, Perspectives Health, Evergrove Labs, Pharmie AI, CareSwift, Careflick, WorkDone, Aegis Health, Mocha Care, Claim Health, Wedge, and MangoDesk are among the S25 companies working in healthcare technology.
Their products span healthcare AI, healthcare IT, pharmacy technology, clinical workflows, healthcare operations, and automation. Healthcare represents one of the strongest vertical-software categories within S25.
Which YC S25 companies are building fintech products?
Y Combinator S25 fintech companies include Magnetic, Altur, Finto, Astor, Veritus Agent, Shor, MochaTrade, Munify, Socratix AI, Iron Grid, and others.
Their products span tax automation, financial services, consumer finance, insurance technology, financial software, and AI applications for finance.
Which YC S25 companies are building robotics or physical AI?
S25 robotics and physical-technology companies include Flywheel AI, Verne Robotics, The Robot Learning Company, Almond, Vassar Robotics, MorphoAI, Zeon Systems, Mbodi AI, Tensr, Efference, Parametric, and others.
These companies span robotics software, computer vision, industrial automation, physical AI, and technologies designed to operate beyond traditional software environments.
Which Y Combinator S25 companies show strong growth signals?
Several Y Combinator S25 companies showed notable activity through funding, adoption, launches, hiring, and commercial expansion.
Vulcan Technologies raised $11 million and expanded hiring across commercial and technical roles. Dedalus Labs raised an $11 million seed round. Albacore raised $6.5 million, while Perseus Defense raised $6 million. Interfere raised $5.1 million and expanded its team. Orange Slice raised $5.3 million and reached more than 5,000 sales and RevOps teams. Pingo reached 300,000 users and $200,000 in monthly recurring revenue. Magnetic processed hundreds of tax returns and expanded hiring.
These signals provide additional context around which S25 companies moved into new stages of growth after joining Y Combinator.
Which YC S25 companies are hiring?
Vulcan Technologies, Luminal, Reacher, Nox Metals, Magnetic, Interfere, Blank Bio, BootLoop, EffiGov, Kalinda, Sira, Novaflow, AgentMail, Orange Slice, TraceRoot, and Solva Technology are among the S25 companies showing hiring activity.
Open roles span sales, growth, engineering, AI infrastructure, security, operations, and other functions, providing additional context on where these companies are expanding.
Why does the Y Combinator S25 batch matter?
The Y Combinator S25 batch captures several important startup themes from 2025, particularly the expansion of AI into specialized industries and business workflows.
S25 companies apply AI and automation to healthcare, software development, sales, finance, robotics, security, compliance, marketing, real estate, education, and productivity. At the same time, companies such as Luminal, Cactus Compute, ZeroEval, Cyberdesk, Idler, Nixo, and Plexe represent the infrastructure layer supporting the broader AI ecosystem.
For GTM teams, the batch provides a useful view into emerging companies entering new stages of product development, fundraising, hiring, adoption, and commercial expansion.
How was this Y Combinator S25 companies list built?
This list was built using Agent Jesse, which helps GTM teams discover companies from live market activity across the web.
The companies on this page were discovered using Agent Jesse, which identifies companies from live startup and market activity, including accelerator participation, funding, hiring, product launches, customer growth, and product adoption.
Frequently Asked Questions About Y Combinator S25
What does YC S25 mean?
YC S25 means Y Combinator Summer 2025, the Y Combinator batch associated with the summer 2025 accelerator cycle. The S stands for Summer and 25 refers to 2025.
When was Y Combinator S25 Demo Day?
Y Combinator S25 Demo Day took place in September 2025. S25 companies including TectoAI and Nox Metals presented during Y Combinator Demo Day in September.
What industries were represented in Y Combinator S25?
Y Combinator S25 included companies across AI, developer tools, healthcare, fintech, robotics, cybersecurity, defense, enterprise software, productivity, biotech, legal technology, PropTech, and other categories. AI was particularly prominent because it appeared across many of these verticals rather than existing only as a standalone category.
What types of AI companies were in YC S25?
YC S25 included companies building AI infrastructure, developer tools, healthcare AI, voice AI, AI security, robotics, financial AI, sales technology, marketing software, AI governance, and productivity tools. Examples include Luminal, Uplift AI, Humoniq, Avelis Health, Phases, Alter AI, Cyberdesk, Fyxer AI, Plexe, and TectoAI.
Where are Y Combinator S25 companies based?
Y Combinator S25 companies are distributed across multiple startup ecosystems, with San Francisco strongly represented alongside companies in New York City, Austin, Detroit, Philadelphia, Chicago, Munich, Mexico City, Amsterdam, and other locations. The batch includes both U.S.-based and international startups.
What happened to YC S25 companies after the batch?
Several S25 companies went on to raise capital, hire employees, launch products, acquire customers, and expand their commercial operations. Examples include Vulcan Technologies' funding and hiring, Dedalus Labs' $11 million seed round, Albacore's $6.5 million financing, Interfere's funding and team expansion, Orange Slice's customer growth, and Pingo's user and revenue growth.
Why are YC accelerator signals useful for lead generation?
Accelerator participation can identify startups at an important stage of company development, while subsequent activity provides additional context around when a company is entering a period of investment or expansion. For GTM teams, these signals can help identify emerging accounts and understand why a company may be worth engaging now.
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