John Gallagher
Principal Engineer at Joyful Programming
Belfast, Northern Ireland, United Kingdom
Summary
👤
Senior🎓
Top SchoolJohn Gallagher is a Principal Engineer with 15 years of experience helping teams ship reliable Rails applications by treating observability as a first-class concern. He led transformations that cut downtime by 98% and 500-errors by 83% through structured logging, instrumentation, runbooks and on-call practices, and also audited telemetry to save $17k/year. A hands-on coach and founder of the Kill3Pill movement, he teaches engineers to fix Rails bugs 20x faster and has turned that work into talks, workshops and a self-published book with strong community traction. His open-source contributions span Ruby and Elixir tooling—improving geocoding, test automation and Selenium infrastructure—and reflect a pragmatic focus on testability and production readiness. Based in Belfast, he combines product-minded engineering with measurable operational wins and a knack for turning firefighting moments into durable process and cultural change.
16 years of coding experience
21 years of employment as a software developer
2-1 MEng Electrical and Electronic Engineering, 2-1 MEng Electrical and Electronic Engineering at The University of BirminghamBTEC National Diploma Engineering, BTEC National Diploma Engineering at Runshaw College7 GCSE's including Science; Maths, 7 GCSE's including Science; Maths at Wellfield High School
Stackoverflow
6,248reputation
620kreached
54answers
69questions
Github Skills (23)
scripting10
elixir10
geocoder10
testing10
ruby10
script10
geocoding10
sh10
google-geocoding-api10
shell10
selenium9
selenium-ide9
integration-testing9
refactoring6
macos6
Programming languages (13)
Github contributions (5)
HashNuke/hound
Jan 2018 - Jan 2018
Elixir library for writing integration tests and browser automation
Role in this project:
DevOps Engineer
DevOps EngineerContributions:11 commits, 1 PR in 4 days
Contributions summary:John's contributions primarily revolve around the project's infrastructure and build process. They modified the Selenium start-up script, increasing the sleep time to accommodate Selenium initialization. Other commits focused on logging improvements within the same Selenium setup script. The user also addressed dependency management by pinning a specific version of the `poison` library.
browser-automationelixir
alexreisner/geocoder
Aug 2013 - Aug 2013
Complete Ruby geocoding solution.
Role in this project:Back-end Developer & QA Engineer / Test Automation Engineer
Back-end Developer & QA Engineer / Test Automation EngineerContributions:5 commits in 1 day
Contributions summary:John focused on enhancing the geocoding functionality, specifically for the Bing geocoding service. Their contributions include implementing features to handle region-specific searches and address sanitization. They also added tests to ensure the correct behavior of the Bing lookup, covering different scenarios such as the presence or absence of region parameters, and testing for spaces in search strings.
geocodingrubygeocoding-apigeocoding-objectsgeocoding-requests
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