Y Combinator companies
The Y Combinator portfolio as the radar sees it: synced daily, classified into clusters, checked for life and movement. 6,198 companies.
clusterVertical AI agents 898Consumer 821B2B SaaS 787Fintech 633Developer tools 515Healthcare and bio 477Commerce and marketplaces 433Agent infrastructure 350Robotics and physical world 314Data for AI 192Security and compliance 189Horizontal AI assistants 152AI infra and compute 152Climate and energy 123Defense and space 85Other 44
| Company | Cluster | Program | Status | Last signal |
|---|---|---|---|---|
| KeyDB The only database you'll ever need | AI infra and computeIn-memory database with flash persistence | Y CombinatorS20 | Acquired | checked 2026-08-23 |
| QuestDB High-performance time series database | AI infra and computetime series database infrastructure | Y CombinatorS20 | Active | checked 2026-08-23 |
| AtmoAI Ultra-precise AI weather forecasting. | AI infra and computeAI weather forecasting infrastructure | Y CombinatorW20 | Active | checked 2026-08-23 |
| Fly.io Run full stack apps close to your users. | AI infra and computedistributed app deployment infrastructure | Y CombinatorW20 | Active | 2026-07-29 |
| ReplicateAI Run machine learning models in the cloud | AI infra and computeModel serving and inference API | Y CombinatorW20 | Acquired | checked 2026-08-23 |
| TermiiAI Termii is an AI-native reliability infrastructure company. | AI infra and computeAI-powered transaction reliability infrastructure | Y CombinatorW20 | Active | checked 2026-08-23 |