My research interests are broadly in distributed systems. I'm currently a Research Scientist at ByteDance's AI Networking team, working on Systems for ML, with a major focus on LLM reliability. My experiences are widely on distributed systems, cloud systems, and AI infrastructure.
- Reliability and observability: distributed tracing, PL for systems towards root cause analysis
- Distributed caching: heterogeneous memory management, CDN caching, performance quantification
- Systems for ML: reliability, observability, performance analysis, RDMA-based AI infra for LLM, Collective Communication Library
My research has been awarded with an ACM SIGMETRICS Kenneth C. Sevcik Outstanding Student Paper Award.
I was a postdoc researcher at Princeton University, working with Prof. Ravi Netravali.
Before that, I received my Ph.D. from Emory University in 2021 (working with Prof. Ymir Vigfusson),
Master from Georgia Tech in 2017(was in Ph.D. program, worked with Prof. Karsten Schwan memorial page ),
and Bachelor from Tsinghua University in 2015.
I transferred to Emory in 2018 as a post-qualified Ph.D. student.
Research Scientist, ByteDance Inc.
2023-current
Postdoc, Princeton University
2022-2023
Research Assistant, Emory University
2018-2021
Teaching Assistant, Emory University
Fall 2020
CS 377: Database Systems
Ph.D. Intern, Facebook Inc.
Summer 2018
Research Assistant, Georgia Tech
2015-2018
Teaching Assistant, Georgia Tech
Fall 2016
CS 3210: Design Operating Systems
Program Committee
USENIX ATC'25
Program Committee
ACM EuroSys'25
External Program Committee
ACM SIGMETRICS'23
Program Committee
ACM SoCC'22, 23, 24
Best Student Paper Award
ACM SIGMETRICS’20
Bronze medal
24th, 25th China Mathematical Olympiad
Thesis:
Measurement and Analysis Methods of Performance Problems in Distributed Systems
Emory University
Thesis
Papers:
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
In USENIX NSDI 2025
Paper
Slides
LatenSeer: Causal Modeling of End-to-End Latency Distributions by Harnessing Distributed Tracing
Yazhuo Zhang, Rebecca Isaacs, Yao Yue, Juncheng Yang, Lei Zhang, Ymir Vigfusson
In ACM SoCC 2023
Paper
Code
The Benefit of Hindsight: Tracing Edge-Cases in Distributed Systems
Lei Zhang, Zhiqiang Xie, Vaastav Anand, Ymir Vigfusson, Jonathan Mace
In USENIX NSDI 2023
Paper
Slides
Code
Benchmark Code
Video
When is the Cache Warm? Manufacturing a Rule of Thumb
Lei Zhang, Juncheng Yang, Anna Blasiak, Mike McCall, Ymir Vigfusson
In USENIX HotCloud 2020
Paper
Slides
Video
Optimal Data Placement for Heterogeneous Cache, Memory, and Storage Systems
Lei Zhang, Reza Karimi, Irfan Ahmad, Ymir Vigfusson
In ACM SIGMETRICS 2020
Paper
Video
Kenneth C. Sevcik Outstanding Student Paper Award
Deceptive Secret Sharing
Lei Zhang, Douglas Blough
In IEEE International Conference on Dependable Systems and Networks (DSN) 2018
Paper
Systematic Data Placement Optimization in Multi-Cloud Storage for Complex Requirements
Maomeng Su, Lei Zhang, Yongwei Wu, Kang Chen, Keqin Li
In IEEE Transactions on Computers 2016, 65(6): 1964-1977.
Paper
Under Review:
Tracing Dependencies in Collective Communication Towards Reliable LLM Training
Towards Bandwidth-adaptive Live Volumetric Video Conferencing
A Lightweight Telemetry System with Service Tracing for Locating Network Slowdowns
Automatic Instrumentation for Fine-grained Observability in Distributed Systems
