RadixArk

RadixArk is an AI infrastructure company spun out of the team behind SGLang, the open-source inference engine that serves trillions of tokens a day for the likes of Google, Microsoft, NVIDIA, Oracle and xAI. Founded by Ying Sheng and Banghua Zhu, RadixArk keeps SGLang and its reinforcement-learning framework Miles free and open while selling managed hosting and tooling on top, aiming to make building, training and running frontier models at least 10x cheaper and 10x more accessible. It launched publicly in May 2026 with a $100M seed round led by Accel and Spark Capital at a $400M valuation.