Ivan Zusko
Senior Frontend Developer at Telefónica
Berlin, Germany
Summary
🤩
Rockstar🎓
Top SchoolIvan Zusko is a Senior Frontend Developer with nine years of experience building performant, developer-friendly web applications across Europe’s top consumer and platform teams. Based in Berlin, he has led frontend initiatives at Delivery Hero and HelloFresh—shaping SDKs, SSO apps, design-system migrations, and conversion-focused UIs while introducing inner-sourcing, monitoring, and coding standards. A React and JavaScript specialist, he pairs hands-on engineering with practical platform thinking, from performance optimizations to observability (Datadog, Sentry). Ivan is also an active open-source contributor, having strengthened type coverage and reliability in the widely used stylelint project by improving Flow annotations and fixing core postcss type issues. His background shows a pattern of turning legacy systems into maintainable products and empowering other developers to contribute. Outside tech, he brings discipline and coaching instincts rooted in his specialist fencing education, which informs his pragmatic leadership style.
9 years of coding experience
10 years of employment as a software developer
Specialist, Fencing coach, Specialist, Fencing coach at National University of Physical Training and Sports, Kyiv
Українська, English, German
Github Skills (11)
linter10
flowtype10
code-coverage10
css10
type-annotations10
work-flow10
postcss10
javascript10
lint10
flow-control10
control-flow10
Programming languages (7)
Github contributions (5)
stylelint/stylelint
Jan 2017 - Sep 2017
A mighty CSS linter that helps you avoid errors and enforce conventions.
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:8 commits, 12 PRs, 43 comments in 8 months
Contributions summary:Ivan contributed significantly to the project by adding flow type annotations and increasing code coverage for existing functionality. Their work included refactoring and improving the type definitions for various modules, including `postcss`, which is a core dependency. Furthermore, the user addressed existing issues and bugs by adding checks, and fixed the issues identified to increase project reliability.
linterlintenforce-conventionssugarsspostcss
ivanzusko/react-dropdowniz
Mar 2017 - May 2017
Contributions:34 commits, 15 pushes, 1 branch in 1 month
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