Steven is part of the Python language tooling team at Meta, currently working on the Pyrefly type checker (https://github.com/facebook/pyrefly)
In addition to his work on first Pyre and then Pyrefly at Meta, Steven helps coordinate activities for the Python typing community and was a co-author of PEP 698 adding an @overload decorator to Python. He has co-hosted the PyCon typing summit the past two years in 2024 and 2025.
Before he got into writing Python language tools, Steven studied mathematics and statistics and spent a number of years working at the intersection of data science and engineering, scientific computing, and building infrastructure to enable teams of scientists.