Oskar Kwaśniewski
Co-Founder & CTO at TesterArmy (YC P26)
Szczecin, West Pomeranian Voivodeship, United States
Summary
🤩
Rockstar🎓
Top SchoolOskar Kwaśniewski is a Co-Founder and CTO with six years of hands-on experience building mobile-first products and developer tooling, currently leading tester.army (YC P26) to rethink how AI-native teams test software. Previously a Senior React Native Developer at Callstack, he brings deep expertise in iOS/Android engineering and React Native core contributions that improved accessibility, navigation, and CLI tooling. His open-source work includes practical platform ports—most notably enabling visionOS support in the widely used bgfx graphics library—and UX-focused utilities like MiniSim for macOS simulator management. Comfortable moving between product-level architecture and low-level rendering/Metal tweaks, he bridges product needs with developer ergonomics. Based in Szczecin, he pairs startup velocity with disciplined engineering from academic training in computer science. He often surfaces non-obvious wins: improving developer workflows (CLI and emulator tooling) that accelerate team shipping velocity as much as user-facing features.
6 years of coding experience
7 years of employment as a software developer
Bachelor's degree, Computer Science, Bachelor's degree, Computer Science at West Pomeranian University of Technology in Szczecin
Github Skills (48)
debugging10
debug10
javascript10
ios10
react-native10
rendering10
typescript10
navigationbar10
ui-design10
render10
appkit10
graphic10
navigation-drawer10
metal10
uid10
Programming languages (16)
Github contributions (5)
okwasniewski/MiniSim
Jan 2023 - Mar 2023
MacOS menu bar app for launching iOS and Android 🤖 emulators
Role in this project:
Mobile Developer (iOS)
Mobile Developer (iOS)Contributions:15 releases, 62 reviews, 51 commits in 1 month
Contributions summary:Oskar primarily contributed to the development of the MiniSim application, focusing on features related to launching and managing iOS simulators. They implemented a global shortcut to invoke the menu, fixed an issue with the status bar icon highlighting, and refactored code by adding menu item types and dividing into smaller functions. The user also added preferences and about pages, along with the ability to delete iOS simulators.
androiddeveloper-toolsiosmenubarmenubar-app
satya164/react-native-tab-view
Aug 2022 - Nov 2022
A cross-platform Tab View component for React Native
Role in this project:Front-end Developer
Front-end DeveloperContributions:1 release, 20 reviews, 11 commits in 2 months
Contributions summary:Oskar primarily contributed to the front-end development of the React Native tab view component. Their work includes refactoring example components to use functional components, updating the example app, and adapting to changes in the core library such as refactoring the tab bar with FlatList. The commits also involve updating dependencies to Expo 47 and pager-view.
view-componentreactpager-componenttabbarreact-native
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.