xviii · 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

4957 commits, 771 PRs, and 275 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/enphase-apichore: measure coverage across the whole workspace12h
JP-Ellis/enphase-apitest(bridge): cover the run loop by extracting its decision logic12h
JP-Ellis/enphase-apifix(bridge): compile the shutdown signal on non-unix targets13h
JP-Ellis/enphase-apitest(bridge): run the reachability classification tests in CI13h
JP-Ellis/enphase-apirefactor(bridge): correct discovery/retry docs, widen availability test13h
JP-Ellis/enphase-apifix(bridge): gate publishing on the broker connection, surface driver exit13h

Latest issues & PRs

JP-Ellis/borrow-checker[PR · open]
feat(beancount): read round-trip files and write working and archive exports10h
JP-Ellis/borrow-checker[PR · open]
feat(sdk)!: plugin exporter interface and native import block10h
JP-Ellis/borrow-checker[PR · merged]
feat(import)!: report each source file's outcome, and fail loudly on a dropped file13h
JP-Ellis/borrow-checker[PR · merged]
feat(csv): accept several date formats, tried in order13h

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