Cumulus Labs

Cumulus Labs is a serverless GPU cloud with a proprietary inference stack, purpose-built for AI teams who want faster performance, lower costs, and zero infrastructure work. If your team uses GPUs — for inference, training, fine-tuning, or any compute workload — Cumulus replaces the painful parts of your stack with a platform that just works. Most teams today are stuck choosing between bad options. Self-hosting inference means wrestling with vLLM or SGLang configurations, debugging CUDA issues, and babysitting infrastructure that breaks at scale. Managed API providers like OpenRouter or Fireworks are convenient but expensive, and you're paying their margin on top of the compute. Serverless GPU platforms give you flexibility but hit you with slow cold starts, idle billing, and no help on the inference layer — you're still on your own to make models run fast. Cumulus eliminates that tradeoff. The platform assigns containers in seconds, scales to zero when you're idle, and scales up to as many instances as you need with no waitlists or approvals. You're billed by the second for exactly the compute you use — nothing more. For inference, Cumulus ships Ion — a proprietary engine that supports all major LLMs, VLMs, and MoE architectures out of the box. Ion is optimized for latency and throughput beyond what teams typically achieve managing vLLM or SGLang themselves, with zero configuration required. Whether you're serving your own fine-tuned model or hosting an open-source model like Llama or Mixtral, Ion handles the performance layer so your team doesn't have to. Cumulus also supports checkpointing, model compilation, and LoRA serving, and the team forward-deploys custom optimizations directly for customers. For training, fine-tuning, and general container workloads, teams bring any job to Cumulus and run it on the same serverless infrastructure — no cluster management, no GPU debugging, no orchestration setup. If you're paying for inference APIs, Cumulus lets you run the same models yourself for less. If you're self-hosting, Cumulus makes your models faster without the operational burden. If you need GPUs for any workload at all, Cumulus is the simplest and most performant way to get them.