Jonatan Kazmierczak
Technical Lead at Class Visualizer
Zurich, Zurich, Switzerland
Summary
👤
Senior🎓
Top SchoolJonatan Kazmierczak is a Technical Lead based in Zurich with nine years of focused experience delivering secure, high-quality software and data solutions across banking, telecom, logistics, and consulting engagements. He founded Class Visualizer, a widely used cross-platform UML tool for Java and Kotlin reverse engineering that attracts over 1,500 downloads per month, demonstrating a long-running commitment to practical open-source tooling. At Zürcher Kantonalbank he leads solution design, data mapping and anonymization work while driving reliability, performance and maintainability through reviews, testing and architectural guidance. Known for top contest results in programming, algorithms and data science, he blends deep hands-on engineering with rigorous quality practices and mentoring. Beyond technology, his work is informed by strong personal values and a servant-leader mindset that shapes team culture and stakeholder trust.
9 years of coding experience
18 years of employment as a software developer
Bachelor's degree, IT Systems Engineer, 5 (best), Bachelor's degree, IT Systems Engineer, 5 (best) at Politechnika Opolskaprofessional, Electrician, 5 (best), professional, Electrician, 5 (best) at ZSEE (Group of Electrical and Electronic Schools) in Zabrze
English, German, Russian, Polish, Ukrainian, Czech, Slovak, Spanish, ewe, twi
Stackoverflow
1,841reputation
655kreached
21answers
1question
java
top-5%
uml
top-5%
Github Skills (30)
gradle10
kotlin10
java-bytecode10
uml9
java9
groovy9
visualizer9
bytecode9
python7
eclipse6
mongodb6
reverse-engineering6
google-chrome-extension6
automation6
netbeans6
Programming languages (3)
Github contributions (5)
jonatan-kazmierczak/words-frequency-calculator
Feb 2019 - Jan 2021
Contributions:45 commits, 19 pushes, 1 branch in 1 year 10 months
jonatan-kazmierczak/articles
Apr 2020 - Aug 2023
Contributions:66 pushes, 1 branch in 3 years 4 months
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