Lianmin Zheng
Co-Founder & AI Systems Researcher
Co-founder of LMSYS Org, PhD researcher at UC Berkeley SkyLab, and creator of SGLang, FastChat, Vicuna, and Chatbot Arena. Pioneered RadixAttention and KV cache reuse runtime optimizations that power state-of-the-art inference engines across the open-weights ecosystem.
Areas of focus
Professional niches
Proof of Work
SGLang: Fast Serving Framework for Complex Language Model Programs
Engineered SGLang featuring RadixAttention, which maintains a radix tree over KV caches to enable automatic multi-turn and prefix cache reuse, delivering up to 5x higher throughput for complex multi-call LLM workflows.
Radix tree traversal introduces slight metadata lookup overhead for workloads with completely random, unshared prefixes.
Context: DeepSeek-V3/R1, LLaMA-3, Qwen-2.5; FlashInfer integration; Triton custom kernels.
View missionJudging LLM-as-a-Judge with MT-Bench and Chatbot Arena
Co-authored the landmark NeurIPS 2023 paper establishing crowd-sourced, blind pairwise human evaluation (Chatbot Arena) and LLM-as-a-judge benchmarks, standardizing empirical foundation model comparison globally.
Susceptible to verbosity and style bias when using automated LLM evaluators without strict length-penalized rubrics.
Context: Crowdsourced human Elo ratings across 1M+ pairwise conversations and GPT-4 automated judgment.
View mission