Peter Ammon
Software Engineer at Oklo Inc
San Jose, California, United States
Summary
🤩
Rockstar🎓
Top SchoolPeter Ammon is a seasoned software engineer with 18 years of experience building performant system software, frameworks, and developer tools from macOS utilities to JavaScript VMs. Based in San Jose, he has shipped low-level, performance-sensitive work at Apple, Google, Facebook (Hermes, React Native), Netflix, and now Oklo, often operating in large, legacy codebases with tight correctness and predictability requirements. His open-source contributions range from optimizing integer division in libdivide to improving bytecode and VM internals (Redex, Hermes) and editing tools like HexFiend, demonstrating a strong focus on compiler/runtime performance, memory correctness, and tooling. Comfortable across C, C++, Objective-C, assembly, Python, and JavaScript, he blends systems expertise with practical engineering—debugging gnarly platform bugs, designing APIs, and improving test suites. Notably, he’s the self-described “fish-shell guy,” hinting at a fondness for pragmatic Unix toolchains and small, well-crafted utilities.
18 years of coding experience
18 years of employment as a software developer
Bachelor's degree, Mathematics, Bachelor's degree, Mathematics at Cornell University
Github Skills (39)
algorithm10
objective-c10
algorithms10
javascript10
c-language10
mobile-development10
react-native10
memory-management10
gt10
c1110
data-structure10
cocoa10
c1710
regular-expression10
javascript-engine10
Programming languages (19)
Github contributions (5)
HexFiend/HexFiend
Nov 2007 - Apr 2018
A fast and clever hex editor for macOS
Role in this project:
Back-end Developer
Back-end DeveloperContributions:329 commits, 2 PRs, 4 pushes in 10 years 7 months
Contributions summary:Peter primarily focused on low-level changes and modifications related to creating a hex editor for macOS. The commits show work being done on core framework files like `HFTextRepresenter.m`, `HFRepresenterTextView.m`, `HFController.m`, and `HFByteArray_FileWriting.m`. The changes include new classes, data structures, and optimizations in the form of a B-Tree data structure for efficient storage. These modifications would enhance data handling, performance, and features such as copy/paste and text insertions within the hex editor.
hexmacoseditorhex-editor
ridiculousfish/libdivide
Aug 2011 - Jun 2022
Official git repository for libdivide: optimized integer division
Role in this project:Back-end Developer
Back-end DeveloperContributions:2 releases, 20 reviews, 93 commits in 10 years 11 months
Contributions summary:Peter primarily contributed to the core functionality of the `libdivide` library, focusing on optimizing integer division by constants. Their work involved implementing codegen references, implementing and optimizing new division algorithms, and improving the test suite. The contributions also involved adding the "branchfree" variants for improved performance and recovery functions.
divisiongit-repositorybyteintegerinteger-division
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