About Me
Hello! I’m Lingyu, an AI Research Engineer at Duolingo. I hold a Ph.D. in Computer Science from Toyota Technological Institute at Chicago, where I worked with Prof. Kevin Gimpel on Natural Language Processing.
My work focuses on LLM-based systems for educational and multilingual applications, especially text retrieval, generation, and evaluation. I am interested in turning ambiguous language problems into measurable, scalable AI systems that connect research with real-world product needs.
- Large Language Models
- Educational & Multilingual AI
- Text Retrieval, Generation & Evaluation
Toyota Technological Institute at Chicago
Ph.D. in Computer Science, M.S. within Ph.D. in Computer Science
Tsinghua University
M.E. in Electrical Engineering, B.E. in Electrical Engineering and Automation
Skills
Python, PyTorch, TensorFlow, SQL, pandas, NumPy
Airflow, BigQuery, AWS, Pinecone, Git, LaTeX
Mandarin, English
Work Experience & Internships
- Building LLM-based systems for educational and multilingual applications, with a focus on retrieval, generation, and evaluation.
- Designing model workflows and evaluation methods that bridge research prototypes and production use cases.
- Fine-tuned LLMs with domain-specific data using supervised fine-tuning and preference optimization.
- Collaborated with test developers, engineers, and scientists on high-quality test item generation.
- Developed multi-agent LLM approaches for automatic scoring.
- Developed demonstration selection methods for retrieval-based in-context learning.
- Improved text classification performance over a strong retrieval baseline and outperformed fine-tuned models on several datasets.
- This work led to a related arXiv preprint.
- Fine-tuned style-specific T5 models for controllable question generation with keyword, topic, and length constraints.
- Improved macro-F1 by 21% over a keyword-extraction baseline.
Publications
Awards & Honors
- 2021: ETS Pre-Doctoral Fellowship
- 2014: Mitsubishi Heavy Industries Scholarship, being one of 25 selected from approximately 180 candidates
- 2013: NARI-RELAYS Scholarship, ranking in the approximate top 15%
- 2011: 1st Grade Academic Excellence Scholarship, placing 6th out of 120 candidates
- 2010: 2nd Grade Freshman Scholarship, ranking 2nd in the entire province
Teaching & Services
Teaching:
- Teaching Assistant, Introduction to Machine Learning (2019)
Reviewer Services:
- Reviewer for ARR, ACL, EMNLP, NAACL-HLT, COLM, CoNLL, BEA, TALLIP, and FigLang
- Secondary Reviewer for EMNLP 2019 and RepL4NLP 2020
Other Services & Activities:
- Research Volunteer, Circle Cat (2023-present)
- Student Member, TTIC DEI Committee and Ph.D. Admissions Committee (2020-2021)