Chi Zhang is a research scientist with a decade of experience building machine learning systems and production-grade ML infrastructure, currently focused on RLHF at ByteDance in Shanghai. He holds a PhD in Computer Science from USC and a strong academic record across multiple international exchange programs, blending deep theory with pragmatic engineering. Chi contributes to prominent open-source RL tooling—most notably volcengine/verl—where he has optimized RL training pipelines, implemented PPO-related improvements, and scaled workflows in Ray-distributed environments. His background spans research internships (eBay) and high-performing academic results, reflecting an ability to translate complex ML research into robust, efficient training systems. Colleagues describe him as someone who quietly improves validation, metrics, and performance bottlenecks that often go unnoticed until they stop working.
10 years of coding experience
Doctor of Philosophy - PhD, Computer Science, Doctor of Philosophy - PhD, Computer Science at University of Southern California
Exchange Program in Fall 2014, Electrical Engineering and Computer Science, Exchange Program in Fall 2014, Electrical Engineering and Computer Science at University of California, Berkeley
Exchange program supported by China Scholarship Council, School of Information Communication and Technology, Exchange program supported by China Scholarship Council, School of Information Communication and Technology at KTH Royal Institute of Technology
Bachelor of Engineering (B.Eng.), School of Information Science and Engineering, 89.0/100, Bachelor of Engineering (B.Eng.), School of Information Science and Engineering, 89.0/100 at Southeast University
verl: Volcano Engine Reinforcement Learning for LLMs
Role in this project:
ML Engineer
Contributions:322 reviews, 198 PRs, 224 pushes in 5 months
Contributions summary:Chi primarily contributes to the reinforcement learning framework, focusing on improvements to the training pipeline. Contributions include fixing issues related to validation, optimizing performance with gradient checkpointing, and refactoring training-related metrics. The user demonstrates knowledge of reinforcement learning concepts like PPO and its implementation within a Ray distributed environment.
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.