Tianyi Peng

Tianyi Peng Assistant Professor, Columbia University Decision, Risk, and Operations Division, Columbia Business School Member of Columbia Data Science Institute Email: tianyi.peng [at] columbia [dot] edu [CV] [GitHub] [linkedin]

About Me

I am broadly interested in AI for decision-making and envision a future where AI agents coexist with humans to enable complex task automation and decision support. My research themes include:

• Ensuring the safe and reliable deployment of AI agents in real-world applications, with continuous alignment and adaptation to business and societal objectives.

• Leveraging AI to simulate human and system behavior (known as “digital twin”), enabling cost-effective, scalable synthetic data generation, experimentation, and testing.

• Reducing the operational costs of AI systems to enable scalable, low-latency deployment across diverse environments.

• Optimizing large-scale decision-making systems through AI and reinforcement learning.

I've collaborated with organizations like Anheuser-Busch InBev, TikTok, and Liberty Mutual. My work with Anheuser-Busch InBev on developing an innovative experimentation platform earned the Daniel H. Wagner Prize in 2022 (INFORMS news). My research has also received the APS Best Student Paper Prize and RMP Jeff McGill Student Paper Award.

I hold a Ph.D. from MIT and a Bachelor's in Computer Science from Tsinghua University (Yao Class).

I am a founding member of Cimulate.AI, developing Customer-GPT for e-commerce. We are hiring!

Publications

(* indicates alphabetical ordering of authors, a celebrated tradition in Operations Research)

• Agents for Web Testing: A Case Study in the Wild
  Naimeng Ye, Xiao Yu, Ruize Xu, Tianyi Peng, Zhou Yu
  [pdf]

• Multi-agent Markov Entanglement
  * Shuze Chen, Tianyi Peng
  

• Twin-2K-500: A dataset for building digital twins of over 2,000 people based on their answers to over 500 questions
  Olivier Toubia, George Z. Gui, Tianyi Peng, Daniel J. Merlau, Ang Li, and Haozhe Chen
  Accepted by Marketing Science Database Track
  [Twin-2K-500 Dataset], [GitHub Documentation]

• Throughput-Optimal Scheduling Algorithms for LLM Inference and AI Agents
  Yueying Li, Jim Dai*, Tianyi Peng*
  

• How Well do LLMs Compress their Own Chain-of-Thought? A Token Complexity Approach
  Ayeong Lee, Ethan Che, Tianyi Peng
  

• Data Mixture Optimization: A Multi-fidelity Multi-scale Bayesian Framework
  Tzu-Ching Yen, Andrew Wei Tung Siah, Haozhe Chen, C. Daniel Guetta, Tianyi Peng, Hongseok Namkoong
  

• LLM Generated Persona is a Promise with a Catch
  Ang Li, Haozhe Chen, Hongseok Namkoong, Tianyi Peng
  

• Differences-in-Neighbors for Network Interference in Experiments
  * Tianyi Peng, Naimeng Ye, Andrew Zheng
  

  • EC 2025

• Speeding up Policy Simulation in Supply Chain RL
  * Vivek F. Farias, Joren Gijsbrechts, Aryan Khojandi, Tianyi Peng, Andrew Zheng
  

  • ICML 2025

• QGym: Scalable Simulation and Benchmarking of Queuing Network Controllers
  Haozhe Chen, Ang Li, Ethan Che, Tianyi Peng, Jing Dong, Hongseok Namkoong
  

  • NeurIPS 2024, Dataset and Benchmarks Track

  • [Code]

• Correcting for Interference in Experiments: A Case Study at Douyin
  * Vivek F. Farias, Hao Li, Tianyi Peng, Xinyuyang Ren, Huawei Zhang, Andrew Zheng
  

  • RecSys 2023

• Markovian Interference in Experiments
  * Vivek F. Farias, Andrew A. Li, Tianyi Peng, Andrew Zheng
  Majore Revision in Management Science
  

  • Winner, Applied Probability Socity (APS) Best Student Paper Prize 2022

  • Winner, Jeff McGill Student Paper Award 2022

  • NeurIPS 2022, Oral (~2%), [Video in Chinese]

• Generalized Synthetic Control for TestOps at ABI: Models, Algorithms, and Infrastructure
  * Luis Costa, Vivek F. Farias, Patricio Foncea, Jingyuan (Donna) Gan, Ayush Garg, Ivo Rosa Montenegro, Kumarjit Pathak, Tianyi Peng, Dusan Popovic
  INFORMS Journal on Applied Analytics
  

  • Winner, Daniel H. Wagner Prize 2022

  • [pdf]

• Learning Treatment Effects in Panels with General Intervention Patterns
  * Vivek F. Farias, Andrew A. Li, Tianyi Peng
  

  • Finalist, MSOM Best Student Paper Prize 2022

  • NeurIPS 2021, Oral (~0.6%)

  • [A Python Package for Causal Inference in Panels]

• Fixing Inventory Inaccuracies At Scale
  * Vivek F. Farias, Andrew A. Li, Tianyi Peng
  Accepted by Manufacturing & Service Operations Management
  

  • MSOM Supply Chain Management SIG 2022

  • ICML 2021
    

• Synthetically Controlled Bandits
  * Vivek F. Farias, Ciamac Moallemi, Tianyi Peng, Andrew Zheng
  Major revision in Management Science
  

  • MSOM Service SIG 2022

• Uncertainty Quantification For Low-Rank Matrix Completion With Heterogeneous and Sub-Exponential Noise
  * Vivek F. Farias, Andrew A. Li, Tianyi Peng
  

  • AISTATS 2022
    

• The Limits to Learning a Diffusion Model
  * Jackie Baek, Vivek F. Farias, Andreea Georgescu, Retsef Levi, Tianyi Peng, Deeksha Sinha, Joshua Wilde, Andrew Zheng
  Management Science

  • Finalist, Post-Pandemic Supply Chain and Healthcare Management Best Paper

  • EC 2021
    

Publications in Quantum (A previous life..)

• Quantum Queuing Delay
  Wenhan Dai, Tianyi Peng, Moe Win
  IEEE Journal on Selected Areas in Communications (IEEE-JSAC), vol. 38, no. 3, pp. 605-618, 2020
  [link], [pdf]

  • Preliminary version: Queuing Delay for Quantum Networks
    International Conference on Computing, Networking and Communications (ICNC 2020)

• Optimal Remote Entanglement Distribution
  Wenhan Dai, Tianyi Peng, Moe Win
  IEEE Journal on Selected Areas in Communications (IEEE-JSAC), vol. 38, no. 3, pp. 540-556, 2020
  [link], [pdf]

  • Preliminary version: Optimal Protocols for Entanglement Swapping and Distribution
    Best Paper Award, International Conference on Computing, Networking and Communications (ICNC 2020)
    

• Simulating Large Quantum Circuits on a Small Quantum Computer
  Tianyi Peng, Maris Ozols, Aram Harrow, Xiaodi Wu
  Physical Review Letters 125, 150504 (2020) (PRL)
  [link] [arxiv]

• Efficient and Robust Physical Layer Key Generation
  Tianyi Peng, Wenhan Dai, Moe Win
  Military Communications Conference 2019 (MILCOM 2019)
  [link]

• Remote State Preparation for Multiple Parties
  Wenhan Dai, Tianyi Peng, Moe Win
  IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2019), Invited Paper
  [pdf], [link]

• Quantum Uncertainty Relation of Coherence
  Xiao Yuan, Ge Bai, Tianyi Peng, Xiongfeng Ma
  Physical Review A 96 (3), 032313 (2017)
  [link] [arxiv]

• Tight Detection Efficiency Bounds of Bell Tests In No-signaling Theories
  Zhu Cao, Tianyi Peng (co-first author)
  Physical Review A 94, 042126 (2016)
  [link] [arxiv]