John Duffell
Software Engineer at Guardian News & Media
London, England, United Kingdom
Summary
🤩
Rockstar🎓
Top SchoolJohn Duffell is a pragmatic software engineer and test specialist with 12+ years’ experience building and automating robust testing frameworks and web features at organisations like IBM and The Guardian. He combines deep technical craftsmanship—writing Java test frameworks, Selenium infrastructure, and REST API tooling—with a flair for process improvement, introducing gates like Checkstyle/FindBugs and SonarQube to raise team quality. A hands-on open-source contributor, he has fixed and optimized components in high-profile projects such as Play Framework and AMP HTML and implemented frontend features for The Guardian. He mentors broadly, from industrial trainees to global tester teams, runs a Scala learning group, and co-created engaging training challenges (a code-cracking “Coding Rally”) that make complex concepts approachable. An inventor with five patent filings (three as lead, one issued) and a history of practical tooling inventions (OWL comparator, page-load detection), he’s as comfortable debugging low-level JVM issues as designing maintainable, auditable test strategies.
11 years of coding experience
12 years of employment as a software developer
Bachelor of Engineering (BEng), Computer Science, 2:1, Bachelor of Engineering (BEng), Computer Science, 2:1 at University of York
Stackoverflow
41reputation
892reached
1answer
2questions
Github Skills (23)
javascript10
ampl10
testing10
css10
google-amp10
java10
scala10
javas10
front-end-development10
html10
web-framework10
playframework10
regular-expression9
restful9
react8
Programming languages (11)
Github contributions (5)
guardian/frontend
Oct 2014 - Jul 2020
The Guardian DotCom.
Role in this project:
Front-end Developer
Front-end DeveloperContributions:11 reviews, 1067 commits, 593 PRs in 5 years 9 months
Contributions summary:John primarily focused on implementing and styling a new banner feature ("FIV banner") within the Guardian's frontend repository. Their work involved creating the banner's basic functionality, including its display logic, user interaction (close button), and integration with other components. They also worked on the banner's visual design, incorporating styling and assets, as well as adding tracking capabilities. Additionally, they added the banner into the wider system, specifically within the app's bootstrapping process.
productionguardian
playframework/playframework
Mar 2018 - May 2021
The Community Maintained High Velocity Web Framework For Java and Scala.
Role in this project:Back-end Developer
Back-end DeveloperContributions:8 commits, 5 PRs, 8 comments in 3 years 2 months
Contributions summary:John contributed to the Play Framework by modifying the `Results` and `CORSActionBuilder` components. Their changes involved URL encoding for redirect parameters, implementing tests for query string handling, and addressing whitespace issues to satisfy code formatters. Further contributions include removing duplicate action execution logic and optimizing URL parameter encoding.
restfulplay-frameworkframeworkplayframeworkjvm
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