xxvii · x · mmxxvi

Hello, again

I codify contracts between systems for a living, in Rust and Python. I once spent five years chasing where the antimatter went.

Senior software engineer at PactFlow (SmartBear). I help lead the open-source Pact Foundation and maintainpact-python; I also wrote tikz-feynman,rust-skiplist, and more.

Previously: data and cloud engineering at KPMG, and doctoral research in theoretical particle physics.

The year in code

5198 commits, 817 PRs, and 276 issues across 37 repositories.

Oct 2025 — Oct 2026
Most of what I make is open. Each square below is one day of my GitHub contributions over the past year.

Latest commits

JP-Ellis/rust-skiplistchore(ci): check doc links in every feature set2d
JP-Ellis/rust-skiplistdocs: link gated items to the features section2d
JP-Ellis/rust-skiplistchore(ci): group additive features in powerset2d
JP-Ellis/rust-skiplistchore(ci): lint every library feature set2d
JP-Ellis/rust-skiplistrefactor: prefer core and alloc over std2d
JP-Ellis/rust-skiplisttest: exercise constructors without entropy2d

Latest issues & PRs

JP-Ellis/rust-skiplist[PR · open]
perf: tighten node walks and drop O(n) scans1d
JP-Ellis/rust-skiplist[PR · open]
test: add hot-path benchmarks and a release CI job1d
JP-Ellis/rust-skiplist[PR · open]
perf(node): lay out node fields hot-first1d
JP-Ellis/rust-skiplist[PR · open]
test(bench): add opt-in large-payload workloads1d

Selected projects

pact-pythonOSS · libraryPython bindings for Pact, rebuilt over a Rust FFI core. Downloaded over 1.3 million times a month.↗ github
tikz-feynmanOSS · LaTeXA LaTeX package for typesetting Feynman diagrams with TikZ; adopted across particle physics with 400+ academic citations.↗ github
rust-skiplistOSS · libraryA skip list for Rust.↗ github
↗ All projects