vi · ix · mmxxvi

Hello, again

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

Senior software engineer at PactFlow (SmartBear). Open source contributor to pact-python,tikz-feynman, rust-skiplist, and more.

Previously: data and cloud engineering at KPMG, and a PhD in theoretical particle physics.

The year in code

3719 commits, 505 PRs, and 183 issues across 35 repositories.

Sep 2025 — Sep 2026
Most of what I make is open. The grid below is the truthful version of a résumé — public, dated, and dense in the parts where I was paying attention.

Latest commits

JP-Ellis/borrow-checkerfix(ci): allow mise ten minutes to install tools6h
JP-Ellis/borrow-checkerfix(ci): drop doc tests from the coverage run6h
JP-Ellis/borrow-checkerstyle: pin tombi line-width and reformat TOML6h
JP-Ellis/borrow-checkerchore: update prek hook revisions7h
JP-Ellis/borrow-checkerchore: lint workflow files with actionlint7h
JP-Ellis/borrow-checkerchore(ci): split E2E out, fold coverage into tests7h

Latest issues & PRs

JP-Ellis/borrow-checker[issue · open]
CSV importer: unknown-key warnings don't cover nested config structs4h
JP-Ellis/borrow-checker[issue · open]
CSV importer: currency-prefixed, comma-grouped amounts fail to parse4h
JP-Ellis/borrow-checker[issue · open]
Add a dedicated importer for periodic balance-and-income statements4h
JP-Ellis/dotfiles[PR · merged]
fix(shell): render man pages through col before bat4h
Selected projects
pact-pythonOSS · libraryPython bindings for Pact, rebuilt over a Rust FFI core. The version most pact-python users actually reach for.↗ github
tikz-feynmanOSS · LaTeXA LaTeX package for typesetting Feynman diagrams with TikZ; adopted across particle physics with 400+ academic citations.↗ github
rust-skiplistOSS · librarySkiplist data structure implementation in Rust.↗ github
↗ All projects