Michał Pierzchała
Head Of Technology at Callstack
Krakow, Lesser Poland Voivodeship
Summary
🤩
Rockstar🎓
Top SchoolMichał Pierzchała is a seasoned software engineer based in Kraków with 11 years of experience specializing in React Native, test automation and developer tooling. An expert React Native developer at Callstack and active member of the Jest and React Native Community teams, he contributes to core projects like facebook/react-native and react-native-testing-library, improving testing primitives and modernizing Android/iOS build and autolinking workflows. His open-source footprint spans Jest, ts-jest, Prettier, CLI tooling and performance testing, reflecting a rare blend of mobile development, QA automation and toolchain integration. Notably, he pairs low-level framework refactors (Flow strictness, ScrollView cleanup) with pragmatic CLI and integration test work to measurably improve developer experience and app reliability.
11 years of coding experience
AGH University
English
Stackoverflow
1,800reputation
129kreached
18answers
1question
unit-testing
top-5%
jasmine
top-5%
jestjs
top-5%
reactjs
top-5%
Github Skills (76)
node-js10
mobile-development10
website-development10
testing10
test-framework10
performance-testing10
webpack410
webpack-410
snapshot-testing10
webpack210
webpack310
javascript10
type-check10
webpack510
webpack-310
Programming languages (17)
Github contributions (5)
callstack/react-native-testing-library
Oct 2018 - Jan 2023
🦉 Simple and complete React Native testing utilities that encourage good testing practices.
Role in this project:
Front-end Developer & QA Engineer / Test Automation Engineer
Front-end Developer & QA Engineer / Test Automation EngineerContributions:51 releases, 251 reviews, 347 commits in 4 years 3 months
Contributions summary:Michał's contributions primarily revolve around enhancing and testing the `react-native-testing-library` repository. They implemented new features, such as adding the `getByType` helper, and refined existing ones, like making `getAllBy*` methods throwable. Additionally, the user added tests to validate the functionalities and ensure the reliability of the library's features. The changes demonstrate a focus on improving the testing capabilities and user experience of the library.
reactreact-native-testingjestreact-nativetesting
react-native-community/cli
Oct 2018 - Jan 2023
The React Native Community CLI - command line tools to help you build RN apps
Role in this project:Mobile Developer (iOS)
Mobile Developer (iOS)Contributions:161 releases, 614 reviews, 432 commits in 4 years 3 months
Contributions summary:Michał primarily focused on improving the React Native CLI tool. Their contributions included migrating the codebase to use modern JavaScript features and Babel transformations, refactoring and improving the linking process for native modules and assets, and adding support for features such as autolinking and improved upgrade functionality. They also made improvements to the iOS build process.
reactyarnreact-nativejavascriptcommand-line-tools
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