Maciej Korzeniewski, Developer in Pyla, Larnaca, Cyprus
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Maciej Korzeniewski

Verified Expert  in Engineering

Mobile Developer

Location
Pyla, Larnaca, Cyprus
Toptal Member Since
July 5, 2022

Maciej is a mobile developer who has been developing, testing, deploying, and maintaining mobile applications both for Android and iOS. He has experience collaborating with teams using the Agile framework and working with native and cross-platform frameworks like Xamarin, Flutter, and React Native. Maciej is skilled in setting up CI/CD pipelines on Jenkins and Bitrise, including automatic building, testing, and deploying to the Google Play Store and App Store.

FirebaseMobileTypeScriptNode.jsReactReduxXamarin.NET CoreDartiOSAndroid

Portfolio

Very Good Ventures
Flutter, Firebase, Mobile
Freelance
Flutter, Firebase, Mobile
LeanCode
Flutter, Firebase, React Native, Xamarin, .NET Core, React, Redux, Mobile

Experience

Mobile - 6 yearsFirebase - 6 yearsFlutter - 4 yearsNode.js - 3 yearsTypeScript - 3 yearsReact Native - 3 yearsAutomated UI Testing - 2 yearsTesting - 2 years

Availability

Full-time

Preferred Environment

MacOS, Slack, Flutter, Firebase, TypeScript, Node.js

The most amazing...

...thing I've done was leading and developing the app Hamilton - The Official App, available for both Android and iOS.

Work Experience

Senior Flutter Developer

2021 - 2022
Very Good Ventures
  • Led the re-architecture of the Hamilton Musical app.
  • Co-developed an open-source web project called Photobooth for the Google I/O event. It allowed people to take a photo, add assets and share it with friends on social media.
  • Co-created apps for Homethrive Inc. with incorporated video streaming using Twilio SDK.
  • Improved testing skills by providing the apps with 100% test coverage.
  • Deployed apps to the App Store and Google Play Store using phased or incremental rollout.
Technologies: Flutter, Firebase, Mobile

Mobile Developer

2020 - 2021
Freelance
  • Co-developed Billy, a home budget assistant app in Flutter and Firebase.
  • Developed communication and engagement skills related to working with clients.
  • Learned how to optimize Firebase Firestore usage for minimal bills.
Technologies: Flutter, Firebase, Mobile

Mobile Developer

2016 - 2020
LeanCode
  • Implemented a GPS tracking module for Android in Kotlin.
  • Co-created Activity Challenges, an activity GPS tracker and game, with React Native and Redux.
  • Developed the Shell Fleet Assistant, a fleet management app in Xamarin and MvvmCross.
  • Added real-time chat functionality with React Native, Redux, and Firebase Firestore for BeautyClick, a finding beauty specialist app.
Technologies: Flutter, Firebase, React Native, Xamarin, .NET Core, React, Redux, Mobile

Hamilton Musical App Recreation

https://hamiltonmusical.com/
• Redesigned the architecture and UI of the old Hamilton app. The multi-layer reactive architecture supports caching to minimize Firestore reads.
• Led a team of 3-6 mobile developers.
• Tested the app (100% test coverage).
• Set up GitHub pipelines to ensure quality code before merging: static code analysis, formatting, and tests.
• Set up automatic store deployment pipelines using Codemagic.
• Deployed the app to stores using a phased rollout technique.
• Maintained the app after release, fixing low-level native, memory-related crashes.

Link to app in Google Play: https://play.google.com/store/apps/details?id=com.hamilton.app

Link to app in App Store: https://apps.apple.com/us/app/hamilton-the-official-app/id1255231054

Frameworks

Flutter, Redux, React Native, .NET Core

Platforms

Firebase, Mobile, Xamarin, iOS, Android

Other

Deployment, Crash Reporting, Crash Fixing, Automated UI Testing, Code Coverage

Languages

TypeScript, Dart

Libraries/APIs

Node.js, React

Paradigms

Testing

Storage

Cloud Firestore

2015 - 2019

Bachelor of Engineering Degree in Computer Science

Warsaw University of Technology - Warsaw, Poland