About

Hi! I am a Computer Science Ph.D. student at Yale University, fortunate to work with Manolis Zampetakis and Andre Wibisono. During my Ph.D., I have also benefited from having great mentors during several professional internships. I will be interning during Summer 2026 at Google as a Student Researcher hosted by Jinoo Baek, Jieru Mei, and Lucas Spangher. In Summer/Fall 2025, I interned at Meta as a Research Scientist Intern hosted by Mandy Chen. In Summer 2024, I interned at Morgan Stanley as a Machine Learning Research Associate hosted by Andrew Bennett.

Prior to starting my Ph.D. studies, I worked at Twitter in the Ads Targeting and Modeling team as a machine learning engineer. Before that, I completed my master’s and bachelor’s degrees together at the University of Pennsylvania, where I was advised by Shivani Agarwal for my master’s thesis.

I am grateful to have received a GFSD (formerly NPSC) fellowship in 2022, sponsored by the U.S. National Security Agency (NSA). I received the Greenberg Fellowship from Yale in 2024. I received my department’s teaching award for 2022-2023.

Research

I am interested in machine learning theory and optimization, particularly when theoretical insights can improve the design and practical use of machine learning algorithms. My research has focused largely on dealing with noise, missing information, and uncertainties in available data.

Publications

(* = alphabetical or equal)

Peer-Reviewed Conferences

• “Learning-Enabled Estimation: Tight Characterizations under Sample Selection Biases” (EC 2026)
  • V. Kher*, J. H. Lee*, A. Mehrotra*, M. Zampetakis* (available soon)
• “Smoothed Analysis of Learning from Positive Samples” (STOC 2026)
  • J. H. Lee*, A. Mehrotra*, M. Zampetakis* pdf
• “Massive Memorization with Hundreds of Trillions of Parameters for Sequential Transducer Generative Recommenders” (ICLR 2026)
  • Z. Chen*, C. Zhao*, K. C. Mo, Y. Jiang, J. H. Lee, S. Chen, K. C. Mahajan, N. Jiang, K. Ren, J. Li, W. Yang pdf
• “Risk-Averse Constrained Reinforcement Learning with Optimized Certainty Equivalents” (NeurIPS 2025)
  • Preliminary version in Duality Principles for Modern Machine Learning Workshop @ ICML 2023
  • J. H. Lee, B. Saglam, S. Pougkakiotis, A. Karbasi, D. Kalogerias pdf
• “Efficient Statistics With Unknown Truncation: Polynomial Time Algorithms Beyond Gaussians” (FOCS 2024)
  • J. H. Lee*, A. Mehrotra*, M. Zampetakis* pdf
• “Learning Exponential Families from Truncated Samples” (NeurIPS 2023)
  • Preliminary version in Workshop on New Frontiers in Adversarial Machine Learning @ ICML 2023
  • J. H. Lee, A. Wibisono, M. Zampetakis pdf
• “Exact Gradient Computation for Spiking Neural Networks Through Forward Propagation” (AISTATS 2023)
  • Preliminary version in Optimization for Machine Learning Workshop @ NeurIPS 2022
  • J. H. Lee*, S. Haghighatshoar*, A. Karbasi pdf
• “Learning from noisy labels with no change to the training process” (ICML 2021)
  • M. Zhang, J. Lee, and S. Agarwal pdf
• “A group-theoretic framework for data augmentation” (NeurIPS 2020, Oral Presentation)
  • S. Chen, E. Dobriban, and J. H. Lee pdf

Journal Articles

• “The rural–urban stress divide: Obtaining geographical insights through twitter” in Computers in Human Behavior
  • K. Jaidka, S. C. Guntuku, J. H. Lee, Z. Luo, A. Buffone, and L. H. Ungar pdf
• “A group-theoretic framework for data augmentation” in Journal of Machine Learning Research (JMLR)
  • S. Chen, E. Dobriban, and J. H. Lee pdf

Teaching

Yale University:

I received the Yale CS Department Distinguished Teaching Award for 2022-2023.

• Probabilistic Machine Learning (CPSC 586), Teaching Fellow (Spring 2023) evaluation
• Introduction to Database Systems (CPSC 537), Teaching Fellow (Fall 2022) evaluation

University of Pennsylvania:

• Machine Learning (CIS 520), Teaching Assistant (Spring 2018, Spring 2019)
• Algorithms (CIS 320), Teaching Assistant (Spring 2019)
• Agent-Based Modeling and Simulation (ESE 520), Teaching Assistant (Fall 2018)
• Internet and Web Systems (CIS 555), Teaching Assistant (Spring 2018)
• Software Engineering (CIS 573), Head Teaching Assistant (Fall 2017)
• Software Engineering (CIS 350), Teaching Assistant (Spring 2017)
• Data Structures and Algorithms (CIS 121), Head Teaching Assistant (Fall 2017), Teaching Assistant (Fall 2016, Spring 2017)

Service and Outreach

I believe that being able to give back to others is a privilege. I have received much help to get to where I am today, and I am glad to be able to help others now. I enjoy volunteering with organizations that help students with meeting their educational needs because I feel that education is one way to empower young people to take control of their futures.

(External) Volunteering:

• Microsoft TEALS Program, Volunteer Teaching Assistant (2021-2024)
• The SMART Program, Volunteer Tutor (2019-2021)

(For those who are interested in getting involved, I highly recommend volunteering with the above organizations. I’ve had a great time working with the staff who are very organized and the students who are eager to learn. The SMART program is local to the the San Francisco Bay Area, but the TEALS program works with high schools throughout the country.)

Service:

• Yale Graduate Student Assembly (GSA)
  • Serivce Committee Chair (2022-2023, 2023-2024)
  • Computer Science Department Representative (2022-2023, 2023-2024, 2024-2025)
• Yale Computer Science Graduate Student Advisory Committee (GSAC)
  • Provisional (Founding) Member (2022-2023)
  • Elected Member (2023-2024)
• Yale Graduate Society of Women Engineers (SWE) Mentorship Program, Graduate Student Mentor (2023-2025)
• Women in Science at Yale (WISAY), Graduate Student Mentor (2021-2025)
• STEM Mentors at Yale, Graduate Student Mentor (2021-2023)
• University of Pennsylvania Women in Computer Science (WiCS) Alumni Mentorship Program, Mentor (Spring 2020)

Miscellaneous

• My sister is also a (really accomplished!) PhD student, in astronomy. Check out her page!
• I just started playing League of Legends Wild Rift on the phone to ease myself into LoL (fellow beginners, duo with me!). I also enjoy Don’t Starve Together, Pokemon games, and am looking for new games to play, so if you are at Yale let me know if you’d like to be friends on any of these (or new) games.
• I also enjoy cooking, fashion, fitness, and painting.