Curriculum Vitae

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Education

• 2024 – 2029 (expected)

  Ph.D. in Industrial Engineering and Operations Research

  University of California, Berkeley

  Ph.D. candidate (passed the qualifying exam in July 2026). Advisor: Prof. Javad Lavaei

• 2020 – 2024

  B.S. in Mathematics

  Tsinghua University, Beijing

  Rank 3 of 55

• Jan – May 2023

  Exchange student

  Cornell University, Ithaca, NY

Experience

• May 2026 – present

  Machine Learning Engineer Intern

  TikTok, Data and Privacy Office · San Jose, CA

  Built an agentic workflow that investigates reported production issues and produces structured repair plans, and improved a privacy-review agent for pre-launch features.

• Jun – Sep 2023

  Quantitative Research Intern, CTA Strategies

  Sixie Capital · Shanghai

  Developed and backtested predictive signals from futures price, volume and order-book data.

Teaching and research appointments

• Fall 2026

  Graduate Student Researcher

  UC Berkeley · with Prof. Javad Lavaei

  Research assistantship supported by NSF funding.

• Fall 2025, Spring 2026

  Graduate Student Instructor, INDENG 160: Nonlinear and Discrete Optimization

  UC Berkeley

Publications and preprints

• 2026

  Groundability, Not Scale Alone: When Weak Reviewers Can Audit Strong Coding Agents

  Junyu Guo, Shangding Gu, Ming Jin, Javad Lavaei

• 2026

  When Context Changes: Understanding Update Failures in LLMs

  Junyu Guo, Yuchen Fang, Shangding Gu, Costas Spanos, James Demmel, Javad Lavaei

• 2026

  LLMs Should Express Uncertainty Explicitly

  Junyu Guo, Shangding Gu, Ming Jin, Costas Spanos, Javad Lavaei

• NeurIPS 2025

  Don't Trade Off Safety: Diffusion Regularization for Constrained Offline RL

  Junyu Guo, Zhi Zheng, Donghao Ying, Ming Jin, Shangding Gu, Costas Spanos, Javad Lavaei

• NeurIPS MATH-AI Workshop 2025

  Meta Thinker: Thinking What AI Thinks

  Junyu Guo, Shangding Gu, Costas J. Spanos, Javad Lavaei

• 2025

  StyleBench: Evaluating Thinking Styles in Large Language Models

  Junyu Guo, Shangding Gu, Ming Jin, Costas Spanos, Javad Lavaei

• 2023

  Reinforcement Learning for SBM Graphon Games with Re-Sampling

  Peihan Huo, Oscar Peralta, Junyu Guo, Qiaomin Xie, Andreea Minca

Academic service

• Oct 2026

  Reviewer, ICLR 2027

  International Conference on Learning Representations

• Aug 2026

  Reviewer, AAAI 2027

  AAAI Conference on Artificial Intelligence

• May 2026

  Reviewer, NeurIPS 2026

  Conference on Neural Information Processing Systems

• Apr 2026

  Reviewer, COLM 2026

  Conference on Language Modeling

• Jan 2026

  Reviewer, ICML 2026

  International Conference on Machine Learning

All service

Honors and awards

• 2024

  Wolff Fellowship

  UC Berkeley

• 2024

  Outstanding Graduate

  Tsinghua University

• 2021

  First Prize, China Undergraduate Mathematics Competition

• 2020 – 2022

  Scholarship for Merit Students

  Tsinghua University

• 2021

  Mathematics Department Academic Scholarship

  Tsinghua University

• 2018, 2019

  First Prize, China High School National Mathematics Olympic League