Pei (Patrick) Chen

Pei (Patrick) Chen

Applied Scientist at Amazon

Amazon

Welcome!

I am an Applied Scientist at Amazon, working across the full LLM mid/post-training stack and the data infrastructure that feeds it, building backbone models for agentic systems. My hands-on work covers 100B+ parameter MoE training on Megatron and Verl/Slime, spanning Continual Pretraining, SFT, DPO, and GRPO, along with a closed-loop data flywheel for scalable post-training. I received my Ph.D. in Computer Science from Texas A&M University, with 20+ publications (8 first-authored) at NeurIPS (Spotlight), ACL, EMNLP, and NAACL, one US patent, and serving as Area Chair at ARR.

Email: chenpei.net@gmail.com
Links: LinkedIn Google Scholar
Office: Santa Clara, CA

Interests
  • LLM Mid/Post-training (CPT with ABF/YaRN, SFT, DPO, GRPO)
  • Data-centric Post-training & Closed-loop Data Flywheel
  • Agentic Systems (multi-agent, tool calling, verifiable rewards)
  • Context Management (Long-context, RAG, Personalization, Multi-turn)
Education
  • Ph.D. in Computer Science, 2019 - 2024

    Texas A&M University

  • MS in Finance, 2016 - 2018

    Southwestern University of Finance and Economics

  • B.Eng. in Simulation Engineering, 2010 - 2014

    National University of Defense Technology

News

  • 2026: 3 papers on multi-turn modeling (via GRPO), personalization, and agentic systems accepted to ACL 2026. ๐ŸŽ‰
  • 2026: Serving as Area Chair for ARR. ๐ŸŽ‰
  • 2026: US Patent 12,530,529 granted for Domain-specific NER via Graph Neural Networks.
  • 2025: 6 papers accepted to NAACL-2025, ACL-2025, and EMNLP-2025, covering long-context modeling, agents, RAG, and post-training data flywheel. โœจ
  • 2024: First-authored long paper (CoMM) accepted to NAACL-2024 โ€” a pioneering multi-agent prompting framework for complex LLM reasoning. ๐Ÿ‘‹
  • 2023: First-authored paper (HYTREL) accepted to NeurIPS-2023 as a Spotlight presentation (top 5%). โœจ

Selected Publications

LLM & Foundation Model Training

Agent

RAG & Long-context & Personalization

Experience

 
 
 
 
 
Applied Scientist
Jan 2024 โ€“ Present Santa Clara, CA
Mid/post-training for agentic LLM systems on 100B+ MoE models. Co-led context management & RAG for Rufus shopping agents, and led the closed-loop post-training data flywheel for customer service.
 
 
 
 
 
Applied Scientist Intern
Jun 2022 โ€“ Aug 2023 Santa Clara, CA
Two internship rotations โ€” produced HYTREL (NeurIPS 2023 Spotlight) and CoMM (NAACL 2024 Findings).
 
 
 
 
 
NLP Researcher Intern
Jun 2021 โ€“ Aug 2021 Remote
Built a benchmark for zero-shot knowledge base completion (ICDM 2022 Workshop).
 
 
 
 
 
Research Engineer & Data Analyst
Chinese Academy of Sciences ยท State Street
Jul 2017 โ€“ Jul 2019 Beijing, China ยท Hangzhou, China
NLP research on financial event extraction and causality detection (CAS); data analysis and visualization for financial applications (State Street).

Misc.

๐Ÿ”ฌ By day: a creative and hands-on LLM scientist with a strong research mindset and a builder’s instinct, excited by bold new ideas in LLMs, AI assistants, and agentic systems. Enjoys exploring emerging directions and turning them into practical solutions for real-world industry problems.

๐Ÿ’ป By night: a geek who reads papers for fun, tinkers with side projects, and has strong opinions about post-training recipes.

๐ŸฅŠ On weekends: 1st DAN in ITF Taekwon-Do, active in swimming, badminton, and boxing โ€” because the best debugging happens after a good workout.