Johannes Fahrenkrug
Independent Software Developer at Springenwerk
Berlin, Germany
Summary
🤩
RockstarJohannes Fahrenkrug is an independent software developer based in Berlin with 17 years of polyglot experience spanning native iOS (Swift, Objective-C), Flutter, and JavaScript/TypeScript, plus recent work in LangChain, embeddings and vector databases. He combines hands-on full-stack contributions to open-source projects—such as bug fixes and test improvements for the Radiant CMS—with commercial freelance work and international security consulting. A regular conference speaker and technical editor, he blends teaching and mentoring with practical engineering, having earned public acknowledgments from companies like Google and Apple. Comfortable across backend and frontend domains, Johannes is equally at home architecting mobile apps, integrating AI tooling, or shoring up web application security.
17 years of coding experience
6 years of employment as a software developer
English, German, French
Stackoverflow
43,862reputation
10.2mreached
299answers
50questions
error-handling
top-5%
semantics
top-5%
ruby
top-5%
postgresql
top-5%
oop
top-1%
nsarray
top-5%
Github Skills (43)
asynchronous10
oop10
ajax10
objective-c10
sql-injection10
git10
ruby-rails10
javascript10
ios10
python10
rubygems10
rspec10
rails10
uistoryboard10
validation10
Programming languages (14)
Github contributions (5)
radiant/radiant
Oct 2011 - Mar 2012
Radiant is a no-fluff, open source content management system designed for small teams.
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:21 commits in 4 months
Contributions summary:Johannes contributed to Radiant CMS by addressing a range of issues across the codebase. Their work included fixing bugs related to configuration handling and regular expressions, and improving the testing suite. They also updated dependencies by integrating the Stringex gem, as well as made enhancements to the instance generator for automated bundle installation. The user's changes touch on both the backend (models, configuration) and frontend (spec files) aspects of the project, showcasing a full-stack development skillset.
content-management-system
jfahrenkrug/abv-calculator-action
Mar 2020 - Aug 2022
A GitHub Action to calculate ABV given the original and final gravity of a beverage. No, it's not very useful.
Contributions:4 PRs, 10 pushes, 5 branches in 2 years 5 months
calculategravitybeverage
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