hi! im tim
i build and study ML systems
these days im training models and watching how they behave, with an eye for making sure their effects on the world are ones all affected stakeholders are satisfied with
what i've been up to:
2025
investigating entity representations in transformer LMs · CHAI
2023–24
MEng CS · MIT
2019–23
BS Physics & BS CS · MIT
reach me at:
Selected Publications
Post-Training 50x Faster
Addie Foote, Rudolf Laine, Timothy H. Kostolansky
blog post, Workshop Labs Blog, March 2026
CoT Red-Handed: Stress Testing Chain-of-Thought Monitoring
Benjamin Arnav*, Pablo Bernabeu-Pérez*, Nathan Helm-Burger*, Timothy H. Kostolansky*, Hannes Whittingham*, Mary Phuong