Ying Sheng is Co-Founder and CEO of RadixArk, an AI infrastructure company on a mission to democratize frontier-level AI infrastructure for developers, startups, and enterprises worldwide.

Ying previously served as an engineer at xAI, where she was a key contributor to the development of SGLang, before departing to co-found RadixArk alongside Banghua Zhu.

In 2023, Ying co-created SGLang, an open-source inference engine for serving large language models at scale, which became a primary alternative to vLLM for high-performance inference and powered xAI's Grok models.

Ying co-founded RadixArk out of the UC Berkeley lab of Databricks co-founder Ion Stoica, where SGLang originated, and is also a co-founder of LMSys, the nonprofit behind SGLang's academic roots.

RadixArk launched in May 2026 with $100M in Seed funding at a $400M valuation, backed by Accel, Spark Capital, NVIDIA's NVentures, AMD, and a star-studded roster of angel investors including the co-founders of xAI, OpenAI, PyTorch, Hugging Face, and Datadog.