Jonathan Protzenko
Tech Lead Manager at Google
Seattle, Washington, United States
Summary
🤩
Rockstar🎓
Top SchoolJonathan Protzenko is a tech lead manager and security-minded engineer with 11+ years blending research and production engineering across Microsoft and Google. He holds a PhD-level background in programming languages and formal methods and has applied that expertise to hardening real-world systems—most notably contributing formally verified, side-channel resistant cryptographic implementations to CPython. At Microsoft he progressed from post-doc to principal researcher, shipping security- and correctness-focused work, and now leads teams at Google from Seattle. He is an active contributor to proof-oriented projects like F* and brings deep experience bridging type theory, verification, and backend engineering. Colleagues describe him as someone who moves smoothly between formal proofs and pragmatic production trade-offs, improving both security and performance. Please use @protz for his public open-source persona.
11 years of coding experience
11 years of employment as a software developer
Ph.D., Computer Science, Ph.D., Computer Science at Université Denis Diderot (Paris VII)MPSI, MP, Mathematics, Physics, MPSI, MP, Mathematics, Physics at Lycée Michel-MontaigneB.S., M.S, Computer Science, B.S., M.S, Computer Science at École normale supérieure de LyonComputer Science, Computer Science at National University of Singapore
English, French, Chinese, Spanish
Stackoverflow
1,719reputation
87kreached
69answers
3questions
Github Skills (19)
md510
dependent-types10
type-check10
sha10
python10
formal-verification10
cryptography10
type-checking10
security9
performance-optimization9
special-characters6
firefox6
encoding6
xul6
firefox-addon6
Programming languages (22)
Github contributions (5)
FStarLang/FStar
May 2015 - Jul 2022
A Proof-oriented Programming Language
Role in this project:
Back-end Developer
Back-end DeveloperContributions:3 reviews, 1397 commits, 102 PRs in 7 years 3 months
Contributions summary:Jonathan appears to be contributing to the F* project, a proof-oriented programming language. The commits focus on the F* Type Checker, with changes to the source code related to handling attributes and type checking. The user seems to be addressing issues in the type checking process by modifying and adding conditions and code modifications.
homotopy-type-theorycoq-librarytype-theorysat-solvercompiler
python/cpython
Nov 2022 - Mar 2025
The Python programming language
Role in this project:Back-end Developer / Security Engineer
Back-end Developer / Security EngineerContributions:42 reviews, 15 PRs, 165 comments in 2 years 5 months
Contributions summary:Jonathan implemented verified implementations of cryptographic primitives within the Python codebase. Their work focused on replacing existing hashlib implementations of SHA2, MD5, SHA1, Blake2, and SHA3 with formally verified, side-channel resistant code from the HACL* project. The user also contributed to adding vectorized versions of Blake2 and fixing an issue in SHA3. Their contributions significantly improved the security and potentially the performance of these fundamental cryptographic functions within the Python ecosystem.
python-programmingprogramming-languagepythonpython-programming-language
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