Keno Fischer
Co Founder CTO (Tools) at JuliaHub
Boston, Massachusetts, United States
Summary
🤩
Rockstar🎓
Top School
Top expert inScientific Computing and Data Science
Keno Fischer is a seasoned engineering leader and co-founder serving as CTO (Tools) at JuliaHub with 14 years of deep systems and language tooling experience. Based in Boston, he has driven core compiler and runtime work for the Julia language and contributed to high-profile open-source projects like JuliaLang/julia, IJulia (the Julia Jupyter kernel), and low-level tooling such as LLVM/Clang and rr. His strengths span compiler internals, automatic differentiation, cross-language interoperability (PyCall, PyJulia, Cxx.jl), and reproducible build systems (Yggdrasil/BinaryBuilder), reflecting a rare blend of research-grade rigor and production-focused engineering. Keno’s contributions often target subtle platform and interoperability edge cases—Windows and macOS compat fixes, syscall handling, and precompilation caching—helping large projects work reliably across environments. Trained in physics and mathematics at Harvard, he brings a principled, analytical approach to building developer tools that scale from notebooks to compilers.
15 years of coding experience
Master of Arts (AM), Physics, Master of Arts (AM), Physics at Harvard University
Stackoverflow
1,407reputation
57kreached
13answers
4questions
julia
top-5%
Github Skills (100)
interoperability10
python10
testing10
windows10
http10
c1110
c1710
gadfly10
pbuilder10
repr10
build-automation10
refactoring10
type-inference10
system-programming10
sparse-matrix10
Programming languages (32)
Github contributions (5)
JuliaInterop/Cxx.jl
Oct 2013 - Nov 2018
The Julia C++ Interface
Role in this project:
Back-end Developer
Back-end DeveloperContributions:3 releases, 390 commits, 65 PRs in 5 years 2 months
Contributions summary:Keno contributed to the Julia C++ Interface, by modifying the code to parse and use C++ types. The user's commits added functions to translate C++ types and expressions. They also modified the code to provide for exception handling and support for C++ array types and other features to make it function like a C++ REPL.
cppjuliacxxffimagic
JuliaMath/openlibm
May 2012 - Oct 2022
High quality system independent, portable, open source libm implementation
Role in this project:Backend Developer
Backend DeveloperContributions:5 reviews, 29 commits, 12 PRs in 10 years 6 months
Contributions summary:Keno primarily focused on addressing compiler warnings and merging code changes within the `openlibm` repository. These changes involved modifications to various source files, specifically targeting issues in mathematical functions such as `fma`, `scalbn`, and `csqrt`. They also made adjustments to the build system, particularly the Makefiles, including fixes for AMD64 Linux and Windows builds and addressing issues with compiler directives.
libmopenlibmmath-libraryccross-platform
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.