About

I am a senior applied scientist at Amazon in Seattle. My first name “Zhiyu” comes from an ancient Chinese poem (好雨知时节), meaning good rain knows the best time to fall. I received my PhD from Lehigh University in 2022, advised by Prof. Brian D. Davison. My research interests lie in natural language processing and information retrieval, with a focus on foundation large language models (LLMs).

Education

Ph.D. in Computer Science

Lehigh University, Bethlehem, PA, USA

2015 – 2022 · GPA 3.97/4.0

Exchange Program

École Supérieure d'Ingénieurs Léonard de Vinci, Paris, France

2014 – 2015 · GPA 15.75/20

B.E. in Computer Science

Nanjing University of Aeronautics and Astronautics, Nanjing, China

2011 – 2015 · GPA 4.2/5.0 (rank 1/94)

Experience

Applied Scientist Intern

Amazon · Seattle, WA, US (remote)

May 2021 – Sep 2021

  • Proposed a reinforcement learning method for conversational question answering, accepted by EMNLP Industry Track 2022.
  • Mentors / Managers: Jie Zhao, Anjie Fang, Besnik Fetahu, Oleg Rokhlenko, Shervin Malmasi.

Applied Science Intern

Zhuiyi Technology · Shenzhen, Guangdong, China

May 2019 – Sep 2019

Applied Science Intern

Bloomberg · Princeton, NJ, USA

Jun 2016 – Aug 2016

  • Analysis of Bloomberg Data License usage patterns.
  • Manager: Michael Liebman.

Publications

2026
  • Efficient Low-Rank Index Routing for High-Dimensional Approximate Nearest Neighbor Search

    Y. Li, S. Wang, Z. Chen, Z. Peng
    Information Processing & Management 2026[pdf]
2025
  • Dependency Relationships-Enhanced Attentive Group Recommendation in HINs

    J. Zhang, Z. Chen, S. Wang, X. Yang, D. Han, Z. Peng
    World Wide Web Journal 2025[pdf]
  • LLM-based Dialogue Labeling for Multiturn Adaptive RAG

    Z. Chen, B. Xie, S. Srinivasan, M. Ramanathan, R. Maragoud, Q. Liu
    EMNLP (Industry) 2025[pdf]
  • REIC: RAG-Enhanced Intent Classification at Scale

    Z. Zhang, M. Yang, Z. Chen, Y. Zhuang, S.-T. Pi, Q. Liu, R. Maragoud, V. Nguyen, A. Beniwal
    EMNLP (Industry) 2025[pdf]
  • Wizard of Shopping: Target-Oriented E-commerce Dialogue Generation with Decision Tree Branching

    X. Li, Z. Chen, J. Choi, N. Vedula, B. Fetahu, O. Rokhlenko, S. Malmasi
    ACL 2025[pdf]
  • Approximate Vector Set Search: A Bio-Inspired Approach for High-Dimensional Spaces

    W. Yang, S. Wang, Z. Chen, Y. Sun, Z. Peng
    ICDE 2025[pdf]
  • Joinable Search Over Multi-Source Spatial Datasets: Overlap, Coverage, and Efficiency

    Y. Li, S. Wang, Z. Chen, S. Chen, Z. Peng
    ICDE 2025[pdf]
2024
  • Identifying High Consideration E-Commerce Search Queries

    Z. Chen, B. Fetahu, J. Choi, S. Malmasi
    EMNLP (Industry) 2024[pdf]
  • Unbiased Learning-to-Rank Needs Unconfounded Propensity Estimation

    D. Luo, L. Zou, Q. Ai, Z. Chen, C. Li, D. Yin, B.D. Davison
    SIGIR 2024[pdf]
  • Enhancing Low-Resource LLMs Classification with PEFT and Synthetic Data

    P. Patwa, S. Filice, Z. Chen, G. Castellucci, O. Rokhlenko, S. Malmasi
    LREC-COLING 2024[pdf]
  • Training-free Optimization of Generative Recommender Systems using Large Language Model Optimizers

    LK. Şenel, B. Fetahu, D. Yoshida, Z. Chen, G. Castellucci, N. Vedula, J. Choi, S. Malmasi
    ACL 2024[pdf]
2023
  • InstructPTS: Instruction-Tuning LLMs for Product Title Summarization

    B. Fetahu, Z. Chen, O. Rokhlenko, S. Malmasi
    EMNLP (Industry) 2023[pdf]
  • Multi-Coner V2: A Large Multilingual Dataset for Fine-grained and Noisy Named Entity Recognition

    B. Fetahu, Z. Chen, S. Kar, O. Rokhlenko, S. Malmasi
    EMNLP (Findings) 2023[pdf]
  • Generate-then-Retrieve: Intent-Aware FAQ Retrieval in Product Search

    Z. Chen, J. Choi, B. Fetahu, O. Rokhlenko, S. Malmasi
    ACL (Industry) 2023[pdf]
  • Answering Unanswered Questions through Semantic Reformulations in Spoken QA

    P. Faustini, Z. Chen, B. Fetahu, O. Rokhlenko, S. Malmasi
    ACL (Industry) 2023[pdf]
  • Model-based Unbiased Learning to Rank

    D. Luo, L. Zou, Q. Ai, Z. Chen, D. Yin, B.D. Davison
    WSDM 2023[pdf]
2022
  • Reinforced Question Rewriting for Conversational Question Answering

    Z. Chen, J. Zhao, A. Fang, B. Fetahu, O. Rokhlenko, S. Malmasi
    EMNLP (Industry) 2022[pdf]
  • StruBERT: Structure-aware BERT for Table Search and Matching

    M. Trabelsi, Z. Chen, S. Zhang, J. Heflin, B. D. Davison
    WWW 2022[pdf]
2021
  • MGNETS: Multi-Graph Neural Networks for Table Search

    Z. Chen, M. Trabelsi, J. Heflin, D. Yin, B. D. Davison
    CIKM 2021[pdf]
  • Neural Ranking Models for Document Retrieval

    M. Trabelsi, Z. Chen, J. Heflin, B.D. Davison
    Information Retrieval Journal 2021[pdf]
  • WTR: A Test Collection for Web Table Retrieval

    Z. Chen, S. Zhang, B. D. Davison
    SIGIR 2021[pdf]
2020
  • A Hybrid Deep Model for Learning to Rank Data Tables

    M. Trabelsi, Z. Chen, J. Heflin, B.D. Davison
    IEEE BigData 2020[pdf]
  • Relational Graph Embeddings for Table Retrieval

    M. Trabelsi*, Z. Chen*, B. D. Davison, J. Heflin
    BigGraphs (at IEEE BigData) 2020[pdf]
  • Towards Knowledge Acquisition of Metadata on AI Progress

    Z. Chen*, M. Trabelsi*, B. D. Davison, J. Heflin
    ISWC (Demo) 2020[pdf]
  • Table Search Using a Deep Contextualized Language Model

    Z. Chen, M. Trabelsi, J. Heflin, Y. Xu, B. D. Davison
    SIGIR 2020[pdf]
  • Pretrained Generalized Autoregressive Model with Adaptive Probabilistic Label Clusters for Extreme Multi-label Text Classification

    H. Ye, Z. Chen, D.-H. Wang, B. D. Davison
    ICML 2020[pdf]
  • Leveraging Schema Labels to Enhance Dataset Search

    Z. Chen, H. Jia, J. Heflin, B. D. Davison
    ECIR 2020[pdf]
2018
  • Generating Schema Labels through Dataset Content Analysis

    Z. Chen, H. Jia, J. Heflin, B. D. Davison
    WWW (Profiles & Data:Search Workshop) 2018[pdf]Best Paper Award

Services

Area Chair

ACL ARR 2023, 2025

Program Committee / Reviewer

  • WSDM 2022–2026
  • NeurIPS 2023–2025
  • SIGIR 2022–2025
  • CIKM 2020, 2025
  • KDD 2022–2025
  • ICLR 2024–2025
  • TheWebConf 2022–2025
  • COLING 2022, 2025
  • NAACL 2025
  • SemEval 2024–2025
  • ECML PKDD 2023–2024
  • EMNLP 2023–2024
  • IJCAI 2023
  • ACL 2023
  • TKDE 2021

Honors & Awards

  • 2021ACM SIGIR Student Travel Grant
  • 2021Rossin Professional Development Program Award, Lehigh University
  • 2020ISWC Student Grant
  • 2020ACM SIGIR Student Travel Grant
  • 2018Best Paper Award — Intl. Workshop on Profiles & Data:Search ’18
  • 2018ACM SIGIR Student Travel Grant
  • 2015RCEAS Dean’s Fellowship
  • 2014Chinese Government Scholarship, China Scholarship Council
  • 2013First Prize, National Mathematical Contest in Modeling (Jiangsu)
  • 2012Honorable Mention for Social Practice
  • 20122nd Prize, 11th Higher Mathematics Competition of Jiangsu Province
  • 2011–14Student Scholarship
  • 2011–14Merit Student

Hobbies

Coffee

I make coffee every day.

🃏

Close-up Magic

Favorite magicians: Richard Turner & Lennart Green.

📷

Photography

Capturing moments.