# Sebastian "Sebo" Diaz

sebodiaz@csail.mit.edu · sdd@mit.edu · seboddiaz@gmail.com · sebodiaz.github.io

_Updated July 2026_

## Overview

- HST MIT PhD candidate in RLE & CSAIL.
- Research interests in machine learning, (convex) optimization, representation learning, generalization, data augmentation, and reinforcement learning.

## Education

- **Massachusetts Institute of Technology** (2023 – May 2028 (expected)) — Ph.D. HST (Computer Science), GPA: 5.00 / 5.00
- **University of Arizona** (2019 – 2023) — B.S. in Biomedical Engineering; Minor in Mathematics, GPA: 3.95 / 4.00

## Industry Experience

- **Machine Learning Research**, Stealth Startup — Kendall Square, Cambridge, MA (May 2026 – Sept. 2026)
  - Post-training V/LLM research in non-verifiable RL settings.

## Fellowships & Awards

- **Graduate Research Fellowship Program**, National Science Foundation (2024)
- **MathWorks Graduate Fellow**, MathWorks (2024)
- **School of Engineering – Distinguished Graduate Student Fellow**, MIT (2023)
- **Program for Exemplary Mentoring Fellow**, MIT (2023)
- **Goldwater STEM Scholarship**, Goldwater Foundation (2022)
- **Sophomore of the Year**, University of Arizona (2021)
- **Native Health Care Scholar**, Udall Foundation (2021)

## Publications

### Lead Author

1. Sebastian Diaz, Polina Golland, Elfar Adalsteinsson, Neel Dey. "Why Invariance is Not Enough for Biomedical Domain Generalization and How to Fix It" (https://arxiv.org/abs/2604.02564). _Preprint: arXiv:2604.02564_, 2026.
2. Sebastian Diaz, Benjamin Billot, Neel Dey, Mingxuan Zhang, Esra Abaci-Turk, Ellen Grant, Polina Golland, Elfar Adalsteinsson. "Robust Fetal Pose Estimation across Gestational Ages via Cross-Population Augmentation" (https://arxiv.org/abs/2509.12062). _Medical Image Computing and Computer Assisted Intervention (MICCAI)_, 2025.
3. Sebastian Diaz, Yamin Arefeen, Borjan Gagoski, Ellen Grant, Elfar Adalsteinsson. "Design of Novel RF Pulse for Fetal MRI Refocusing Trains Using Rank Factorization (SLfRank) to Reduce SAR and Improve Image Acquisition Efficiency" (https://cds.ismrm.org/protected/22MProceedings/PDFfiles/2926.html). _International Society for Magnetic Resonance in Medicine (ISMRM)_, 2022.

### Contributing Author

1. Yingcheng Liu, Peiqi Wang, Sebastian Diaz, Benjamin Billot, Esra Abaci-Turk, Ellen Grant, Polina Golland. "Fetuses Made Simple: Modeling and Tracking of Fetal Shape and Pose" (https://arxiv.org/abs/2506.17858). _Medical Image Computing and Computer Assisted Intervention (MICCAI)_, 2025.
2. Molin Zhang, Nicolas Arango, Sebastian Diaz, Jacob White, Elfar Adalsteinsson. "Stochastic-Offset-Strategy Enhanced RF Pulse Optimization with Auto-Differentiation" (https://submissions.mirasmart.com/ISMRM2024/Itinerary/PresentationDetail.aspx?evdid=5606). _International Society for Magnetic Resonance in Medicine (ISMRM)_, 2024.
3. Ricky Cordova, Kelli Kiekens, Susan Burrell, William Drake, Zaynah Kmeid, Photini Rice, Andrew Rocha, Sebastian Diaz, Shigehiro Yamada, Michael Yozwiak, Omar L. Nelson, Gustavo C. Rodriguez, John Heusinkveld, Ie-Ming Shih, David S. Alberts, Jennifer K. Barton. "Sub-Millimeter Endoscope Demonstrates Feasibility of In Vivo Reflectance Imaging, Fluorescence Imaging, and Cell Collection in the Fallopian Tubes". _Journal of Biomedical Optics_, 2021.

## Invited Talks

- **RepreSeg: Stable Representations for Domain Generalized Segmentation** — MIT IMES Seminar, Cambridge, MA (Dec. 12, 2025)
- **Learning Alongside Invariant Representations: Robust Generalization in Medical Imaging** — MIT IMES Department Retreat, Boston, MA (Sept. 29, 2025)

## Relevant Coursework

- **MIT**: Deep Learning, Numerical Methods, Computer Vision, fMRI Neuroscience
- **Harvard Medical School**: Pathology, Immunology, Genetics, Cardiovascular & Pulmonary Pathophysiology

## Skills

- **Programming**: Python, PyTorch, C++
- **Technical**: Numerical optimization, probability

## Service

- **Reviewer**, MICCAI: PIPPI (2025–26)
- **Reviewer**, CVPR (2026)
- **Reviewer**, NeurIPS (2026)