Philip N. Hagelberg

email: phi¡no spam thank you!l@hagelb.org

pronouns: he/him


Expert in Fennel, Clojure, Emacs Lisp, and Lua. Experience with Erlang, Racket, OCaml, Elixir, Forth, Scheme.
Knowledgeable concerning GNU Emacs, GPG, Leiningen, LÖVE, and more.

Free Software Contributions

Contributed to:
GNU Emacs, Clojure, Ruby, Rails, TIC-80, Pleroma, RubyGems, Clojars, Microscheme, Hpricot, Magit, and more
Took over Maintenance of:
Fennel, Logplex, Swank Clojure, Clojure Mode, and package.el
Leiningen, Emacs Starter Kit, Atreus, Grenchman, Slamhound, Bus Scheme, and several games.


Work Experience

CircleCI December 2016 - present

  • Team Lead on the Billing team responsible for tracking usage and payment of all customers.
  • Mentored new hires including training several people with no Clojure experience to the point where they could contribute productively to a Clojure codebase.

Atreus Keyboards December 2014 - January 2020

  • Created and documented a design for a small keyboard to be constructed from readily-available DIY parts.
  • Wrote three USB keyboard firmwares from scratch for the ATMega32u4 chip.
  • Started and ran a small business selling and supporting kits and keyboards to a worldwide customer base.

Heroku October 2011 - December 2014

Sonian April 2009 - September 2011

  • Helped design and implement a document parsing, indexing, and archival pipeline in Clojure which functioned at petabyte level.
  • Developed Leiningen project automation tool originally for our in-house needs, which got turned into a public project with many thousands of users and hundreds of contributors.


Fully remote since 2009.

Voraciously self-taught.

Native English speaker, conversant in Bahasa (Indonesian/Malaysian). Beginner-level Thai and beginner-level Mandarin.

Bachelor of Science degree in Computer Science, Magna Cum Laude.