The inference platform
for production AI.
Cumulus Labs consolidates the eight things every production AI team builds for themselves — gateway, router, cache, observability, evaluation, fine-tuning, custom hosting, and the inference engine — into a single platform with a single API.
Make production inference
a configuration choice.
AI teams should not have to assemble seven vendors plus a cloud GPU rental to ship an inference product. Cumulus exists so that routing, caching, observability, evaluation, fine-tuning, and the runtime itself can be one platform behind one API — and so the engineers who would have built that stack can build the product instead.
Eight subsystems.
One platform.
OpenAI-compatible HTTP layer. One client, every provider.
Declared per-workflow routing. Deterministic. Traceable.
Exact-match, prefix, and semantic caches. Stacked.
Every request logged. Replayable audit log.
Synthetic data, heuristics, judges, shadow evaluation.
One-click LoRA training on captured traffic.
Bring open weights or fine-tunes. Served on Ion.
Custom attention kernels on NVIDIA Grace and Blackwell.
Backed by
Y Combinator (W26)
Selected for the Winter 2026 batch — building alongside the world-class founders defining the next decade of AI infrastructure.
NVIDIA Inception
Member of NVIDIA's program for the highest-leverage startups working at the frontier of AI and accelerated compute.
Founded by alumni from
Engineers and operators out of defense, finance, and the institutions that built modern GPU compute.
What we believe
Speed is a Feature
Every millisecond of inference latency multiplies across every user, every request. We optimize the runtime itself.
Simplicity Over Complexity
The best inference platform is invisible. Change one line. Keep your code. The seven other vendors disappear.
Open by Default
Any model. Any provider. Any framework. The router decides — and you can override it at any time.