# Ying Sheng

> Ying Sheng is the co-founder and CEO of RadixArk, an AI infrastructure company that spun out of SGLang, the open-source inference engine she helped create in 2023. SGLang now runs across hundreds of thousands of GPUs and serves trillions of tokens a day for Google, Microsoft, NVIDIA, xAI and others. A Stanford computer science PhD and former xAI technical staff who co-led the inference team behind Grok, she launched RadixArk in May 2026 with $100 million in seed funding led by Accel at a $400 million valuation, on a mission to make frontier-level AI infrastructure open and accessible to everyone.

- **Role:** Co-Founder & CEO at RadixArk
- **Organizations:** RadixArk, SGLang, LMSYS, Stanford University
- **From:** China
- **Nationality:** Chinese
- **Education:** Ph.D. in Computer Science (advised by Clark Barrett, Centaur group), Stanford University, M.S. in Computer Science, Columbia University, B.E. in Computer Science and Technology (ACM Honored Class), Shanghai Jiao Tong University
- **Known for:** Co-founder and CEO of RadixArk, which raised $100M in seed funding at a $400M valuation, Co-creator of SGLang, the open-source LLM inference engine deployed across hundreds of thousands of GPUs and serving trillions of tokens daily, Co-led the inference team behind xAI's Grok models

## Career timeline

- **2015** — Research intern at Microsoft Research Asia with Chin-Yew Lin
- **2016** — Graduated from the ACM Honored Class at Shanghai Jiao Tong University
- **2017** — Earned M.S. in Computer Science at Columbia University
- **2018** — Quantitative software engineer at Two Sigma; ACM ICPC World Finalist
- **2021** — Research intern at Facebook Novi on smart contract verification with David Dill
- **2022** — Ph.D. resident at X, the Moonshot Factory, working on AI for Code with Michele Catasta
- **2023** — Created SGLang within the LMSYS research group; visiting researcher at UC Berkeley Sky Lab with Ion Stoica and Joseph Gonzalez
- **2024** — Joined xAI as member of technical staff, co-leading the inference team behind Grok
- **2025** — Left xAI in August; began building RadixArk with co-founder Banghua Zhu
- **2026** — Launched RadixArk publicly with $100M seed funding led by Accel at a $400M valuation

## Achievements

- Co-founder and CEO of RadixArk, which raised $100M in seed funding at a $400M valuation
- Co-creator of SGLang, the open-source LLM inference engine deployed across hundreds of thousands of GPUs and serving trillions of tokens daily
- Co-led the inference team behind xAI's Grok models
- Contributor to widely used open-source projects including FlexGen, S-LoRA, FastChat, Vicuna and the cvc5 theorem prover
- a16z Open Source AI Grants (2023 and 2025)
- ML Commons Rising Stars 2023
- Stanford HAI Graduate Fellowship (2022-2023)
- Best Tool Paper, TACAS 2022
- Best Paper, IJCAR 2020
- ACM ICPC World Finalist (2018) and Greater New York Champion (2017)
- NOI (National Olympiad in Informatics, China) Silver Medal (2011)

## Latest updates

- **2026-05** — RadixArk launched publicly with $100 million in seed funding led by Accel and co-led by Spark Capital, at a $400 million post-money valuation.
- **2025-08** — Left xAI to start RadixArk with co-founder Banghua Zhu, bringing along core SGLang developers and ecosystem contributors.

## Links

- Website: https://sites.google.com/view/yingsheng/home
- LinkedIn: http://www.linkedin.com/in/yingsheng1123
- Twitter/X: https://x.com/ying11231
- GitHub: https://github.com/Ying1123

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Profile page: https://yespress.io/ying-sheng
Published by YesPress — https://yespress.io
Last updated: 2026-06-20