Greg Pfeil
Independent Software Consultant at Self-employed
Boulder, Colorado, United States
Summary
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Rockstar🎓
Top SchoolGreg Pfeil is an independent software consultant and functional-programming specialist with 20+ years of experience building compilers, language tools, and high-assurance systems from startups to large tech firms. He pairs deep expertise in Common Lisp, Haskell, Scala, and dependently typed languages (Idris) with hands-on systems work—contributing to recognized projects like Clozure CL, Dhall, Zcash, and the Emacs Projectile ecosystem. Greg has architected compiler IRs and multiple backends, improved performance-critical systems, and led technical work that spans DSP, relational theory, and process calculi. Based in Boulder, he blends pragmatic engineering (including low-level runtime fixes and caching optimizations) with a taste for “designing terrible languages,” and delights in solving the unglamorous problems that make software robust and maintainable.
19 years of coding experience
22 years of employment as a software developer
Music Composition Computer Science, Music Composition Computer Science at James Madison University
English
Stackoverflow
86reputation
112reached
1answer
0questions
Github Skills (52)
c-language10
type-check10
theming10
project-management10
top-level10
testing10
projectile10
ui-customization10
dhall10
user-interface10
data-structure10
emacs-lisp10
scala10
typer10
custom-ui10
Programming languages (31)
Github contributions (5)
sellout/emacs-color-theme-solarized
Apr 2011 - Oct 2017
Emacs highlighting using Ethan Schoonover’s Solarized color scheme
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:9 reviews, 143 commits, 43 PRs in 6 years 7 months
Contributions summary:Greg primarily contributed to theming and styling aspects of the Emacs color theme. Their commits focused on modifying color definitions, adjusting face definitions, and integrating changes from other contributors, including adapting to different Emacs versions. They were responsible for the addition of various customizations to enhance the theming capabilities and fixing several styling-related issues. The user’s work also involved adapting the theme for low-color terminals.
schemeorg-modeethanemacssolarized
precog/matryoshka
Jun 2014 - Jul 2017
Generalized recursion schemes and traversals for Scala.
Role in this project:Back-end Developer
Back-end DeveloperContributions:920 commits, 78 PRs, 47 pushes in 3 years 1 month
Contributions summary:Greg's commits primarily involve enhancements to the codebase for recursion schemes and traversals in Scala. Their contributions include responding to PR feedback, adding tests for existing functions, refactoring code, and implementing new operators for set operations. The user's focus appears to be on the core functionality of the project, including making internal structures for the data type and more generalized operations. They also worked on improving the performance of the library.
functional-programmingrecursion-schemesscalajsscalaschemes
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