Zijin (Gavin) FENG

AI Researcher

Hong Kong

zijingavin [AT] gmail.com

About

I am currently an AI researcher in Hong Kong, building LLM agents that reason, prove, and code. My work connects agent design, Lean-based verification, foundation-model post-training, and large-scale diffusion language models.

I received my Ph.D. from The Chinese University of Hong Kong, supervised by Prof. Hong Cheng, with a research focus on LLMs and data mining. I earned my B.Sc. with First Class Honors in Computer Science from Hong Kong Baptist University under Prof. Jianliang Xu. I also held research appointments at the University of Auckland and Aalborg University.

Research internships: I welcome enquiries from students with strong computer science and mathematics backgrounds who are interested in LLM agents for coding and mathematical reasoning, formal reasoning, or reinforcement learning. Please email your CV and research interests.

Research Interests

LLM & Coding Agents

Interactive agents, trajectory data, and rigorous evaluation for reliable tool use on real-world software tasks.

Verifiable Mathematical Reasoning

Lean-integrated theorem proving, autoformalization, and reasoning agents with executable verification.

Foundation-Model Post-Training

SFT, DPO, and GRPO for stronger reasoning and more reliable model behavior.

Diffusion Language Models

Large-scale pretraining and stable reinforcement learning for discrete diffusion LMs.

Recent Highlight

I led the development of a theorem-proving agent that achieved gold-medal-level performance on the 2026 IMO problems, state-of-the-art Pass@1 on MathOlympiad (86%) and Putnam (88%), and first prize in the ICML 2026 AI4Math Challenge.

Selected Publications

Selected work in ICML, ICLR, NeurIPS, SIGMOD, EMNLP, and ICDE. See Google Scholar for the complete list.

† Corresponding author · Brief: challenge, method, evidence.

2026

  1. J. Zhong, K. Wang, D. Ding, Z. Feng†, H. Bai, Y. Xiang, J. Sun, Q. Xu
    International Conference on Machine Learning (ICML)
  2. A. Ospanov, Z. Feng†, J. Sun, H. Bai, X. Shen, F. Farnia
    International Conference on Machine Learning (ICML)
  3. Z. Feng, X. Yu, J. Zhong, P. Zhai, R. Yousef, W. C. Ng, et al.
    International Conference on Learning Representations (ICLR)
  4. R. M. Cabral, T. M. Do, X. Yu, W. M. Tai, Z. Feng, X. Shen
    International Conference on Learning Representations (ICLR)
  5. F. Ding, D. Ding, S. Chen, K. Wang, P. Xu, Z. Feng, H. Bai, et al.
    International Conference on Learning Representations (ICLR)
  6. T. Xie, S. Xue, Z. Feng, T. Hu, J. Sun, Z. Li, C. Zhang
    International Conference on Learning Representations (ICLR)

2025

  1. Z. Feng, M. Qiao, C. Piao, H. Cheng
    ACM SIGMOD International Conference on Management of Data (SIGMOD)
  2. S. Chen, S. Nie, J. Sun, Z. Feng, Z. Li, J. Wen, C. Li
    Conference on Neural Information Processing Systems (NeurIPS)

2024

  1. Z. Feng, L. Lin, L. Wang, H. Cheng, K. F. Wong
    Empirical Methods in Natural Language Processing (EMNLP)
  2. Z. Feng, M. Qiao, H. Cheng
    ACM SIGMOD International Conference on Management of Data (SIGMOD)

2022

  1. Z. Feng, M. Qiao, H. Cheng
    IEEE International Conference on Data Engineering (ICDE)

2020

  1. Z. Feng, T. Liu, H. Li, H. Lu, L. Shou, J. Xu
    IEEE International Conference on Data Engineering (ICDE)