Hang Zhu


             Hang Zhu

            Research Scientist
            ByteDance@Seattle
       
            E-mail: hangzhu16 [AT] gmail [DOT] com

Bio

I am a Research Scientist in the machine learning system group at ByteDance@Seattle. I obtained my PhD degree from Johns Hopkins University in 2022, advised by Prof. Xin Jin. I received my bachelor's degree from Tsinghua University, China. My current focus is on building large-scale training systems for large language models.

Education

  • Ph. D. in Department of Computer Science, Johns Hopkins University, 2017 - 2022
  • B.E. in Department of Automation, Tsinghua University, 2013 - 2017

    • Publications

  • VAPO: Efficient and Reliable Reinforcement Learning for Advanced Reasoning Tasks
    Yufeng Yuan, Qiying Yu, Xiaochen Zuo, Ruofei Zhu, Wenyuan Xu, Jiaze Chen, Chengyi Wang, TianTian Fan, Zhengyin Du, Xiangpeng Wei, Gaohong Liu, Juncai Liu, Lingjun Liu, Haibin Lin, Zhiqi Lin, Bole Ma, Chi Zhang, Mofan Zhang, Wang Zhang Hang Zhu, Ru Zhang, Xin Liu, Mingxuan Wang, Yonghui Wu, Lin Yan
    [Arxiv 2025]
  • Dapo: An open-source llm reinforcement learning system at scale
    Qiying Yu, Zheng Zhang, Ruofei Zhu, Yufeng Yuan, Xiaochen Zuo, Yu Yue, Tiantian Fan, Gaohong Liu, Lingjun Liu, Xin Liu, Haibin Lin, Zhiqi Lin, Bole Ma, Guangming Sheng, Yuxuan Tong, Chi Zhang, Mofan Zhang, Wang Zhang, Hang Zhu, Jinhua Zhu, Jiaze Chen, Jiangjie Chen, Chengyi Wang, Hongli Yu, Weinan Dai, Yuxuan Song, Xiangpeng Wei, Hao Zhou, Jingjing Liu, Wei-Ying Ma, Ya-Qin Zhang, Lin Yan, Mu Qiao, Yonghui Wu, Mingxuan Wang
    [Arxiv 2025] [Project]
  • Minder: Faulty Machine Detection for Large-scale Distributed Model Training
    Yangtao Deng, Xiang Shi, Zhuo Jiang, Xingjian Zhang, Lei Zhang, Zhang Zhang, Bo Li, Zuquan Song, Hang Zhu, Gaohong Liu, Fuliang Li, Shuguang Wang, Haibin Lin, Jianxi Ye, Minlan Yu
    NSDI, 2025
    [PDF]
  • Klotski: Efficient and Safe Network Migration of Large Production Datacenters
    Yihao Zhao*, Xiaoxiang Zhang*, Hang Zhu, Ying Zhang, Zhaodong Wang, Yuandong Tian, Alex Nikulkov, Joao Ferreira, Xuanzhe Liu, Xin Jin
    SIGCOMM, 2023
    [PDF]
  • NetVRM: Virtual Register Memory for Programmable Networks
    Hang Zhu, Tao Wang, Yi Hong, Dan R. K. Ports, Anirudh Sivaraman, Xin Jin
    NSDI, 2022
    [PDF] [Slides]
  • Network Planning with Deep Reinforcement Learning
    Hang Zhu, Varun Gupta, Satyajeet Singh Ahuja, Yuandong Tian, Ying Zhang, Xin Jin
    SIGCOMM, 2021
    [PDF] [Slides(long)] [Slides(short)] [Code]
  • Runtime Recovery of Web Applications under Zero-Day ReDoS Attacks
    Zhihao Bai, Ke Wang, Hang Zhu, Yinzhi Cao, Xin Jin
    S&P, 2021
    [PDF] [Slides(long)] [Slides(short)] [Code]
  • RackSched: A Microsecond-Scale Scheduler for Rack-Scale Computers
    Hang Zhu, Kostis Kaffes, Zixu Chen, Zhenming Liu, Christos Kozyrakis, Ion Stoica, Xin Jin
    OSDI, 2020
    [PDF] [Slides(long)] [Slides(short)] [Code]
  • Multitenancy for Fast and Programmable Networks in the Cloud
    Tao Wang, Hang Zhu, Fabian Ruffy, Xin Jin, Anirudh Sivaraman, Dan R. K. Ports, Aurojit Panda
    HotCloud, 2020
    [PDF] [Slides]
  • Harmonia: Near-Linear Scalability for Replicated Storage with In-Network Conflict Detection
    Hang Zhu, Zhihao Bai, Jialin Li, Ellis Michael, Dan R. K. Ports, Ion Stoica, Xin Jin
    VLDB, 2020
    [PDF] [Slides]
  • Neural Packet Classification
    Eric Liang, Hang Zhu, Xin Jin, Ion Stoica
    SIGCOMM, 2019
    [PDF] [Slides] [Code]
  • BitCuts: A Fast Packet Classification Algorithm Using Bit-Level Cutting
    Zhi Liu, Shijie Sun, Hang Zhu, Jiaqi Gao, Jun Li​
    Computer Communications, 2017

    • Services

  • Technical program committee: NSDI'25, SIGCOMM'23 Posters/Demos
  • Artifact evaluation program committee: MLSys'23
  • Conference reviewer: INFOCOM'22, INFOCOM'21, INFOCOM'20
  • Journal reviewer: ToN'23, ToCC'21, ToN'21

    • Teaching

  • Teaching Assistant at Johns Hopkins University, Fall 2019
    EN.601.714 Advanced Computer Networks
  • Teaching Assistant at Johns Hopkins University, Spring 2019
    EN.601.414/614 Computer Networks
  • Teaching Assistant at Johns Hopkins University, Spring 2018
    EN.601.414/614 Computer Networks