John Kelly
Quantitative Developer
London, England, United Kingdom
Summary
🤩
Rockstar🎓
Top SchoolJohn Kelly is a quantitative developer with eight years of engineering experience focused on low-latency optimisation, compilers, and type theory, working primarily in Rust and C++. Based in London and trained in Electronic & Information Engineering at Imperial College, he bridges hardware-aware thinking with production-grade software for finance and systems work. He has contributed to high-profile open-source projects such as rust-clippy—adding lints to catch duplicated trait bounds—and the .NET runtime, optimizing vector ops and intrinsics. His roles at firms including Quadrature, Marshall Wace, and Hero Health reflect a pattern of shipping performance-critical backend systems for trading and healthcare. Aside from hands-on coding, he brings a compiler-minded approach to API and runtime design, turning type-level insights into practical optimisations. He maintains a technical portfolio at johnk.dev that highlights both research interests and applied systems work.
8 years of coding experience
1 year of employment as a software developer
A Levels Maths Physics and Computer Science, A Levels Maths Physics and Computer Science at Magdalen College School, OxfordBachelor of Engineering - BE Electronic & Information Engineering, Bachelor of Engineering - BE Electronic & Information Engineering at Imperial College London
c++, c#, python, javascript, rust, c
Github Skills (13)
net10
asp-net10
linting10
clippy10
dotnet10
rust10
intrinsics10
csharp10
vectorization10
dotnet-core10
testing10
math-functions9
api-design8
Programming languages (17)
Github contributions (5)
dotnet/runtime
Feb 2019 - Feb 2021
.NET is a cross-platform runtime for cloud, mobile, desktop, and IoT apps.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:1 review, 8 commits, 12 PRs in 1 year 11 months
Contributions summary:John primarily contributed to improving the .NET runtime, focusing on areas related to vector operations, pointer manipulation, and mathematical functions. They addressed documentation issues, optimized existing code, and added new API surfaces for better functionality. Their work also involved implementing specific intrinsics, optimizing math functions, and adding tests to ensure proper functionality.
dotnetruntimelinuxcsharpxamarin
rust-lang/rust-clippy
Apr 2023 - May 2023
A bunch of lints to catch common mistakes and improve your Rust code. Book: https://doc.rust-lang.org/clippy/
Role in this project:Backend Developer
Backend DeveloperContributions:3 reviews, 1 PR, 4 comments in 8 days
Contributions summary:John primarily contributed to the `clippy_lints` portion of the repository. Their commits focused on implementing and refining a lint rule for identifying and suggesting improvements related to trait bounds. These changes involved modifying the Rust code, specifically the `trait_bounds.rs` file, to detect and suggest changes for duplicated trait bounds in trait declarations. The user's work included adding and refining the lint check logic, making suggestions for code improvements, and updating the tests to validate the new lint behavior.
linterlintrustlangmistakes
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