Tobias von Arx
Tobias von Arx

Hey! I'm a Data Science Master's student at ETH Zurich; currently visiting the University of Cambridge.

I'm interested in machine learning, security, and language models. I've worked on LLMs + security at the ETH SRI Lab and at UBS, pretraining and memorization dynamics with the ETH AI Center, and applied machine learning across oncology and the geospatial domain.

I enjoy hybrid athletics, playing the guitar, discussing ethics; and have plenty of mini-obsessions such as chess, geoguessr, fractals, and many other things.

I'm always happy to discuss interesting ideas---please reach out!

tobiasvonarx [at] proton [dot] me
CV, LinkedIn, GitHub, and X.

Research

AutoBaxBuilder: Bootstrapping Code Security Benchmarking Tobias von Arx, Niels Mündler, Mark Vero, Maximilian Baader, Martin Vechev ICML 2026

Agentic generation of web-backend security benchmark tasks with functional tests, contrastive exploits, and an executable benchmark release.

Memorization Dynamics of Fill-in-the-Middle Pretraining Tobias von Arx*, Tanguy Dieudonné* (*equal contribution) MemFM @ ICML 2026

Controlled 100B+ token pretraining experiments, studying FIM vs. left-to-right memorization through probabilistic extraction and attention patterns.

Writeups