Mikołaj Leszczyński
Senior Android Engineer at Whatnot
Gdańsk, Pomeranian Voivodeship, Poland
Summary
🤩
Rockstar🎓
Top SchoolMikołaj Leszczyński is a Senior Android Engineer with 11 years of experience building scalable, user-focused mobile apps from startups to large enterprises. He has driven architecture and tooling improvements at companies like Babylon Health—where he led a Java-to-Kotlin migration and authored the Orbit MVI framework—and now shapes Android at Whatnot. Known for moving teams from MVP to MVI, introducing coroutine-first SDKs, and designing end-to-end testing strategies, he blends hands-on engineering with strong architecture leadership. An active open-source contributor and core developer of orbit-mvi, he focuses on refactoring, StateFlow-based state management, and Compose helpers to improve developer ergonomics. Based in Gdańsk, he pairs a pragmatic, metrics-driven approach with a passion for mentoring and sharing knowledge through talks and articles. Colleagues describe him as continually improving both products and people, often spotting and fixing subtle API or event-loop issues before they reach production.
11 years of coding experience
10 years of employment as a software developer
Master of Science (MSc), Computer Software Engineering, Master of Science (MSc), Computer Software Engineering at Technical University of Gdansk
Polish, English, German
Github Skills (5)
kotlin10
mvi-architecture10
mvi-android10
kotlin-multiplatform10
compose10
Programming languages (2)
Github contributions (5)
orbit-mvi/orbit-mvi
Jan 2021 - Jan 2023
A simple MVI framework for Kotlin Multiplatform and Android
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:36 releases, 174 reviews, 43 commits in 2 years
Contributions summary:Mikołaj primarily focused on refactoring and updating the project's codebase. They moved packages to follow organization naming conventions, updated links and copyright notices, and refactored code to use StateFlow for state emissions. Additionally, the user addressed explicit API mode issues, fixed an event loop issue and added compose helper functions. This indicates a focus on improving the project's structure and usability.
mvi-androidkotlin-coroutineskotlin-multiplatformmvvmcoroutines
robotoworks/composter
Jan 2017 - Sep 2020
Contributions:10 commits, 9 pushes, 1 branch in 3 years 8 months
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