Justin Hsu

Justin Hsu is an associate professor of computer science. Previously, he was an assistant professor in the Department of Computer Sciences at the University of Wisconsin–Madison, and a postdoc in the Department of Computer Science at Cornell University and in the Programming Principles, Logic, and Verification Group at the University College London. He obtained his Ph.D. from the Department of Computer Science at the University of Pennsylvania. 

Hsu designs methods to formally verify that algorithms are correct. He is especially interested in programs satisfying quantitative guarantees, or other properties from mathematical or scientific applications.

A particular focus of his work has been verifying programs that use randomization. Such programs can be easy to show correct on paper, but surprisingly challenging for computers to analyze. Drawing inspiration from how humans reason about randomized algorithms, he can build simpler and more automated verification techniques. In the past, he has applied this approach to properties like statistical accuracy, incentive compatibility, Markov chain mixing, algorithmic stability, and differential privacy.

More broadly, Hsu is interested in verification for all kinds of programs with rich mathematical structure and properties, such as continuous-time systems, programs with symmetries, economic mechanisms, runtime monitors for hierarchical policies, and algorithms from numerical analysis and applied mathematics.