Michał J
Staff Frontend Engineer at Confidential
Gdańsk, Pomeranian Voivodeship, Poland
Summary
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Rockstar🎓
Top SchoolMichał J is a Staff Frontend Engineer with over 14 years of hands-on experience building high-traffic B2B, B2C and C2C marketplaces, including significant work on Allegro and merXu. He specializes in JavaScript/TypeScript, Vue.js, React and Node.js, and brings strong HTML5/CSS expertise to production-grade, microservice-driven frontends. With an MSc in Mathematics, he applies mathematical reasoning and statistical rigor to A/B testing, data analysis and product design decisions, often complementing findings with Python/Jupyter workflows. He’s equally comfortable shaping UX in Figma, performing thorough code reviews, and owning features from ideation through deployment. Known for pragmatic architecture choices—splitting systems into micro-parts where it matters—he has led teams and technical initiatives at startups and larger platforms alike. Based in Gdańsk, Poland, he combines deep frontend craft with a rare quantitative mindset that surfaces non-obvious, evidence-backed improvements.
14 years of coding experience
15 years of employment as a software developer
MSc, Mathematics, MSc, Mathematics at Uniwersytet Kazimierza WielkiegoElectronics and telecommunications, Electronics and telecommunications at Uniwersytet Technologiczno-Przyrodniczy im. Jana i Jędrzeja Śniadeckich w Bydgoszczy
German, English, Polish
Stackoverflow
69reputation
8kreached
6answers
0questions
Github Skills (183)
react-carousel10
padding10
rectangle10
realms10
image-slider10
timepicker10
javascript10
urlsearchparams10
morph10
react-component10
headless-browser10
visual-regression-testing10
datepicker10
byte10
phantomjs10
Programming languages (5)
Github contributions (5)
msn0/grunt-variablize
Apr 2014 - Feb 2016
Contributions:17 commits, 1 PR, 1 push in 1 year 10 months
javascriptvariablejsonjson-file
elstats/percentile
Mar 2018 - Jul 2021
Calculate n-th percentile of an observation variable
Contributions:3 releases, 13 commits, 14 pushes in 3 years 5 months
calculatevariableobservationpercentile
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