Jiachen T. Wang
Also known as Tianhao Wang
Jiachen Wang studies data-centric approaches to trustworthy machine learning. He studied computer science and statistics at Waterloo, earned an MEng at Harvard, and completed a doctorate in electrical and computer engineering at Princeton in May 2026. His work includes robust data valuation, online selection of language-model training batches, and attribution within a single training run; ICLR gave the last work an Outstanding Paper Honorable Mention in 2025. He was named a Rising Star in Data Science in 2024 and received a 2025 Apple Scholars in AI/ML PhD fellowship. After serving as a student researcher at Google Research in 2025 and 2026 and co-organizing ICLR's DATA-FM workshop in 2025, he is a research scientist on ByteDance Seed's Pretrain Data team, a role he began in July 2026.
Timeline
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2016–2019
Computer science at Waterloo
He earns a B.S. in computer science and statistics at the University of Waterloo in 2019 and works closely with Prof. Florian Kerschbaum.
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2019–2026
Harvard MEng and Princeton PhD
He earns an MEng in computational science and engineering at Harvard in 2021, where he works with Prof. Salil Vadhan. He completes a Ph.D. in electrical and computer engineering at Princeton in May 2026 under Prof. Prateek Mittal, and works closely with Prof. Ruoxi Jia at Virginia Tech.
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2023
Data Banzhaf and KNN-Shapley
In 2023, he and Ruoxi Jia publish Data Banzhaf, which finds that the Banzhaf value can preserve data rankings when stochastic gradient descent makes model scores noisy. At NeurIPS in 2023, he and his coauthors present Threshold KNN-Shapley, a linear-time, privacy-friendly data valuation method that supports differential privacy.
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2024
GREATS for LLM data selection
At NeurIPS in 2024, he coauthors GREATS, an online method that selects data batches during LLM training and improves convergence speed and generalization. He is named a Rising Star in Data Science in 2024.
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2025
Data Shapley in one training run
In 2025, ICLR gives Data Shapley in One Training Run an Outstanding Paper Honorable Mention; Jiachen T. Wang is one of its authors. The method attributes data contributions to a target model from a single training run. He also receives a 2025 Apple Scholars in AI/ML PhD fellowship.
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2025–2026
Google Research and DATA-FM
He works as a student researcher at Google Research in 2025 and 2026, collaborating with Lin Chen, Mohammadhossein Bateni and Vahab Mirrokni. He co-organizes the second DATA-FM workshop at ICLR in 2025, which addresses data challenges in foundation models.
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2026
Proxy runs for data curation
In 2026, he coauthors a study of how small proxy runs can guide data curation for large-scale LLM training. It finds that data-quality conclusions can change with small adjustments to training hyperparameters and proposes reduced learning rates to make proxy evaluations more reliable.
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Since July 2026
Research scientist at ByteDance Seed
He joins ByteDance Seed's Pretrain Data team as a research scientist in July 2026.
Career
- Since 2026ByteDanceResearch scientist
- 2025–2026Google ResearchStudent researcher
Education
- 2026Princeton UniversityPh.D.
- 2021Harvard UniversityMEng
- 2019University of WaterlooB.S.
Sources and credits
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- Jiachen T. Wang
- Data Banzhaf: A Robust Data Valuation Framework for Machine Learning
- Threshold KNN-Shapley: A Linear-Time and Privacy-Friendly Approach to Data Valuation
- GREATS: Online Selection of High-Quality Data for LLM Training in Every Iteration
- Announcing the Outstanding Paper Awards at ICLR 2025
- Data Shapley in One Training Run
- DATA-FM Workshop @ ICLR 2025
- Can Small Training Runs Reliably Guide Data Curation? Rethinking Proxy-Model Practice


