Inferact

Inferact is founded and led by the core creators and maintainers of vLLM, the widely-used open-source inference engine that determines how efficiently AI models actually run once deployed. The company's thesis is that as models get more capable, the systems serving them — not the models themselves — become the real bottleneck, and it is building commercial infrastructure around vLLM to close that gap. vLLM itself now supports 500+ model architectures across 200+ accelerator types, with contributions from over 2,000 open-source community members, and in August 2026 became the first inference engine to complete full Kimi K3 vendor verification. The founding team includes Simon Mo and Woosuk Kwon (vLLM's original creators), UC Berkeley professor Ion Stoica (also a co-founder of Databricks and Anyscale), Joseph Gonzalez, Roger Wang, and Kaichao You. Inferact raised $150M in a Seed round in January 2026 at an $800M valuation, led by Andreessen Horowitz and Lightspeed Venture Partners, with Sequoia, Altimeter, Redpoint, Databricks Ventures, and the UC Berkeley Chancellor's Fund among the other participants — an unusually large seed round reflecting how central vLLM already is to production AI infrastructure before Inferact even had a commercial product.