Ian Ker-seymer
Senior Staff Software Engineer at Shopify
Atlanta, Georgia, United States
Summary
🤩
Rockstar🎓
Top SchoolIan Ker-seymer is a Senior Staff Software Engineer with 12 years of experience building developer tooling and production engineering at scale, currently at Shopify in Atlanta. He blends deep Ruby ecosystem expertise with systems work in Rust—contributing to core projects like Ruby itself and RubyGems by adding Rust extensions and improving build and CI tooling. Ian is comfortable across the stack, from front-end UX improvements in React components to backend concurrency primitives and parser-server performance work that reduced Ruby parsing overhead. He has a track record of leading engineering orgs and mentoring startups, and brings practical automation skills that surface in improved test suites, build reliability, and CI hygiene. Known for a hands-on, make-break-rinse-repeat approach (and a penchant for low-level fixes hinted by his GitHub one-liner), he pairs pragmatic problem-solving with a knack for developer experience.
12 years of coding experience
13 years of employment as a software developer
CourseraBachelor's degree Computer Science Psychology, Bachelor's degree Computer Science Psychology at University of Colorado at BoulderWoodward Academy
English
Github Skills (35)
programming-language10
javascript10
cargo10
rubygems10
atomics10
testing10
generator10
wpgraphql10
data-structure10
cicd10
ruby10
pretier10
gemspec10
gemfile10
performance-optimization10
Programming languages (25)
Github contributions (5)
ruby/ruby
Feb 2015 - May 2023
The Ruby Programming Language
Role in this project:
Back-end Developer & Automation Engineer
Back-end Developer & Automation EngineerContributions:8 reviews, 2 PRs, 16 comments in 8 years 4 months
Contributions summary:Ian contributed to the Ruby programming language project by primarily focusing on the build process and testing infrastructure for the RubyGems component. Their work involved upgrading dependencies like `rb-sys`, ensuring build configurations always use release mode, and improving existing tests. Furthermore, the user integrated and addressed clippy linting issues within the YJIT component and incorporated RbSys's `ExtensionTask` for new Rust gem creation, indicating proficiency in managing builds and CI/CD.
object-orientedruby-languageprogramming-languagerubyc
rubygems/rubygems
Jun 2018 - Dec 2022
Library packaging and distribution for Ruby.
Role in this project:Back-end Developer
Back-end DeveloperContributions:26 reviews, 132 commits, 19 PRs in 4 years 7 months
Contributions summary:Ian primarily contributed to the implementation of a Rust extension for the rubygems/rubygems repository. Their work involved creating a `cargo_builder`, which would allow for Rust extensions to be built and integrated into RubyGems. They added tests to verify functionality, including both static and dynamic library builds. The user also addressed the use of environment variables, and corrected some errors in code.
rubygemspackagingpackage-managerrubymruby
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