Sunny Qin

I am a final-year PhD candidate at Harvard, advised by Sham Kakade and David Alvarez-Melis, and a member of the Machine Learning Foundations Group.

I work on data-centric machine learning and reinforcement learning. I am broadly interested in the science of foundation models, particularly how natural and synthetic training data interact with learning algorithms to shape model behavior and capabilities.

I'm honored to be a 2027 Siebel Scholar and a 2025 Apple Scholar in AI/ML.

During my PhD, I have also spent time as a research intern at Apple (summer 2025) and Google Research (summer 2026).

Blog Posts

RL Excursions thumbnail
RL Excursions during Pre-training: Re-examining Policy Optimization for LLM Training
Backtrack Thumbnail
To Backtrack or Not to Backtrack: When Sequential Search Limits Model Reasoning
Unknowable Thumbnail
Distinguishing the Knowable from the Unknowable with Language Models

Research

* Equal contribution.

Data-Centric Machine Learning & Scaling
Bridging Compute- and Data-Optimal Pretraining
Tian Qin*, Kimia Hamidieh*, David Alvarez-Melis.
NeurIPS 2026 Oral · Top 1% [ArXiv]
Scaling Laws · Data Repetition · Synthetic Data
RL Excursions during Pre-Training: Re-examining Policy Optimization for LLM Training
Rachit Bansal*, Clara Mohri*, Tian Qin*, David Alvarez-Melis, Sham Kakade.
NeurIPS 2026 [ArXiv] [GitHub]
Training Pipeline · RL · Data Composition
Random Scaling of Emergent Capabilities
Rosie Zhao*, Tian Qin*, David Alvarez-Melis, Sham Kakade, Naomi Saphra.
ICML 2026 [ArXiv]
Scaling Laws · Emergent Capabilities · Data Composition
Sometimes I am a Tree: Data Drives Unstable Hierarchical Generalization
Tian Qin, Naomi Saphra, David Alvarez-Melis.
EMNLP 2025 [ArXiv]
Training Data · Hierarchical Generalization · Learning Dynamics
A Label is Worth A Thousand Images in Dataset Distillation
Tian Qin, Zhiwei Deng, David Alvarez-Melis.
NeurIPS 2024 [ArXiv] [GitHub]
Dataset Distillation · Data Efficiency
Distributional Dataset Distillation with Subtask Decomposition
Tian Qin, Zhiwei Deng, David Alvarez-Melis.
DMLR @ ICLR 2024 [ArXiv] [GitHub]
Dataset Distillation · Data Compression
RL, Reasoning & Agents
To Backtrack or Not to Backtrack: When Sequential Search Limits Model Reasoning
Tian Qin, David Alvarez-Melis, Samy Jelassi, Eran Malach.
COLM 2025 [ArXiv]
LLM Reasoning · Test-Time Scaling
COMPASS: Benchmarking Constrained Optimization in LLM Agents
Tian Qin, Felix Bai, Ting-Yao Hu, Raviteja Vemulapalli, Hema Swetha Koppula, Zhiyang Xu, Bowen Jin, Mert Cemri, Jiarui Lu, Zirui Wang, Meng Cao.
COLM 2026 [ArXiv] [GitHub]
LLM Agents · Constrained Optimization · Tool Use
Distinguishing the Knowable from the Unknowable with Language Models
Gustaf Ahdritz*, Tian Qin*, Nikhil Vyas, Boaz Barak, Benjamin L. Edelman.
ICML 2024 [ArXiv] [GitHub]
Uncertainty · Representations · Calibration
Decomposing Elements of Problem Solving: What "Math" Does RL Teach?
Tian Qin*, Core Francisco Park*, Mujin Kwun, Aaron Walsman, Eran Malach, Nikhil Anand, Hidenori Tanaka, David Alvarez-Melis.
Preprint [ArXiv]
RL · LLM Reasoning · Generalization
AI + Science
Meta-PDE: Learning to Solve PDEs Quickly Without a Mesh
Tian Qin*, Alex Beatson*, Deniz Oktay, Nick McGreivy, Ryan P. Adams.
Preprint [ArXiv]
Meta-Learning · PDE Solvers · Scientific ML

Invited Talks

  • Google DeepMind Frontier AI team, August 2026. "Bridging Compute- and Data-Optimal Pretraining". [Slides]
  • Deep Learning: Classics and Trends (DLCT), October 2025. "Distributional Scaling Laws for Emergent Capabilities". [Event] [Slides]
  • Nvidia, July 2025. "What 'Math' Does RL Teach?" [ArXiv]
  • Seminars on Formal Languages and Neural Networks, March 2025. "Data Drives Unstable Hierarchical Generalization in LMs". [Recording]
  • Voxel 51 Boston AI, ML and Computer Vision Meetup, Feb 2025. "A Label is Worth a Thousand Images in Dataset Distillation". [Event]

Teaching & Service

Personal

Outside research, I enjoy spending my free time outdoors — climbing all sorts of things: rocks, boulders, big wall, frozen waterfalls, and big mountains. I am a board member and an education officer of the Harvard Mountaineering Club. I also recently got into surfing!

Contact

Email: tqin[AT]g.harvard.edu