Bartosz Sumper
Staff Software Engineer at Software Mansion
Krakow, Lesser Poland Voivodeship
Summary
👤
Senior🎓
Top SchoolBartosz Sumper is a Staff Software Engineer with 11 years of experience specializing in React Native, TypeScript and GraphQL, currently leading mobile engineering efforts for Chime through Software Mansion. He combines hands-on implementation—shipping performance improvements like a ~70% faster cold start and server-driven UI migrations—with people leadership, having mentored ~10 engineers and conducted 500+ technical interviews and assessments. Comfortable operating across frontend, native SDKs and backend integrations, he’s delivered realtime features via GraphQL subscriptions and optimized client-server interactions for scale. Based in Krakow, he has successfully run distributed teams across time zones for over seven years, treating asynchronous communication as a core engineering discipline. Beyond coding, Bartosz has shaped hiring and onboarding processes, scoring take-home assignments and training recruiters and mentors to raise hiring quality. He’s pragmatic about tooling and developer experience, driving initiatives like custom ESLint rules and CI checks to improve stability and velocity.
11 years of coding experience
5 years of employment as a software developer
Mathematics and Physics, Mathematics and Physics at The M. Skłodowska-Curie High School in AndrychówMagister inżynier (Mgr inż.) Informatyka, Magister inżynier (Mgr inż.) Informatyka at AGH University of Krakow
Polish, English, bokmål, norweski
Github Skills (44)
javascript10
ios10
react-native10
animation10
animated10
cross-platform10
gesture10
android10
react10
mobile9
relay9
graphql8
react-native-paper8
rails8
app-framework8
Programming languages (6)
Github contributions (5)
barsumek/ScalaGame
Jan 2016 - Oct 2016
Contributions:2 commits, 1 PR, 1 push in 9 months
scalastar-warswars
software-mansion-labs/poke-workshops
Nov 2018 - Nov 2019
Workshops for teaching React Native and Expo
Contributions:10 commits, 2 PRs, 4 pushes in 1 year
reactreact-native-paperreact-nativeteachinguser-guide
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