Jingjing Li
Jingjing Li

Senior Machine Learning Engineer

About Me

Jingjing Li is a Senior Machine Learning Engineer at Roblox, where she develops models for text safety across the Roblox platform. Previously, she was an Applied Scientist at TikTok, where she built multilingual conversational LLM agents for global customer service. Her research interests center on LLM safety, alignment, and reasoning. She received her Ph.D. in Computer Science and Engineering from The Chinese University of Hong Kong.

Education
  • PhD in Computer Science

    The Chinese University of Hong Kong

  • B.Eng. in Computer Science

    Xidian University

Experience

  1. Senior Machine Learning Engineer

    Roblox
    • Working on LLM post-training and evaluation for text safety and content moderation.
    • Built lightweight ML models for real-time PII detection, supported by LLM-assisted synthetic data generation and labeling.
  2. Applied Scientist

    TikTok E-Commerce
    • Post-trained multilingual LLMs for global customer service at TikTok Shop, covering response generation, intent classification, and routing.
    • Built tool-using AI agents and automated evaluation pipelines for multi-turn workflows, rapid iteration, and deployment.
  3. Applied Scientist Intern

    Tencent Lightspeed Studios
    • Developed LLM-driven autonomous agent system for a game demo, winning 1st place in the company-wide innovation competition.
  4. Applied Scientist Intern

    Amazon Alexa AI
    • Analyzed semantic fidelity in neural data-to-text models. Proposed a novel decoding strategy to improve semantic accuracy and entity correctness (+8%) over state-of-the-art models (BART, T5).
  5. Research Intern

    Microsoft Research Asia
    • Investigated unsupervised text generation in data-scarce settings. Developed an iterative in-place text span editing approach, achieving state-of-the-art performance on unsupervised text simplification (AAAI 2022).

Education

  1. PhD in Computer Science

    The Chinese University of Hong Kong
  2. B.Eng. in Computer Science

    Xidian University
    National Scholarship, Ministry of Education of China
Selected Publications

* denotes co-first authorship.

Fast, Slow, and Tool-augmented Thinking for LLMs: A Review. Frontiers of Computer Science (FCS), 2026.
Entropy-Based Decoding for Retrieval-Augmented Large Language Models. NAACL, 2025.
SeRTS: Self-Rewarding Tree Search for Biomedical Retrieval-Augmented Generation. Findings of EMNLP, 2024.
CLongEval: A Chinese Benchmark for Evaluating Long-Context Large Language Models. Findings of EMNLP, 2024.
A Survey of Text Watermarking in the Era of Large Language Models. ACM Computing Surveys, 2024.
Text Revision by On-the-Fly Representation Optimization. AAAI, 2022.
Unsupervised Text Generation by Learning from Search. NeurIPS, 2020.
Improving Question Generation With to the Point Context. EMNLP-IJCNLP, 2019.