Cumulus Labs
Cumulus Labs is a YC Winter 2026 (W26) company. Based in San Francisco, CA, USA. Team of 2.
About Cumulus Labs
Summary
Cumulus Labs builds a full-stack AI inference platform for teams running fine-tuned and open-source models. Its three products cover GPU orchestration (Paladin), multimodal inference for text, vision, and audio (Ion), and agent fine-tuning and evaluation (Talos). The platform replaces the choice between self-managed GPU infrastructure and expensive hosted providers by handling orchestration, kernel optimization, and deployment in one place.
Business model
API access to hosted models plus dedicated deployments on Cumulus GPUs or customer hardware.
Go-to-market
AI engineering teams at B2B companies are the buyers; they can start via self-serve API access or book a demo for dedicated deployment.
From the Y Combinator listing
The Fastest Multimodal Inference OS
Cumulus Labs is a fast multimodal inference provider, purpose-built for AI teams who want faster performance, lower costs, and zero infrastructure work on fine-tuned & open source models. Most teams today are stuck choosing between bad options. Self-hosting inference means wrestling with configurations and babysitting infrastructure that slows/breaks at scale. Big providers like Fireworks are convenient but extremely expensive and idle GPUs. Cumulus ships Ion, a proprietary inference engine that run LLMs, VLMs, and audio/video gen with high performance and lower cost.
Facts
- B2B / B2B -> Infrastructure
- San Francisco, CA, USA
- 2
- Active
- Early
Founders (2)
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