toptal.com
Contact us: +1.888.867.7001
Andrzej Chmielewski, Software Developer in Wrocław, Poland
Andrzej Chmielewski

Software Developer in Wrocław, Poland

Member since January 19, 2017
Andrzej is a highly motivated Android developer trying to be best at what he does. He is constantly learning new things and looking for more opportunities to grow his skills. He tries not to overcomplicate problems, keeping in mind that the code he writes is like a publication: It must be understandable and easy to read to as many people as possible. He's a big proponent of clean code and clean architecture. He's a UX-first thinker.
Andrzej is now available for hire
Hire Andrzej

Portfolio

  • OkFuture
    Flutter, Firebase Test Lab, GraphQL, TypeScript, Model View Presenter (MVP)...
  • Ignite
    Team Leadership, Technical Leadership, Flutter, Firebase Test Lab...
  • Ease (formely EaseCentral)
    Mobile, Android SDK, Android Testing, Android, iOS, Swift, Kotlin...

Experience

Location

Wrocław, Poland

Availability

Full-time

Preferred Environment

MacOS, GitHub, Git, Android Studio, IntelliJ

The most amazing...

...thing I've experienced is being featured twice on Androidweekly.net for articles and open source libraries I've created.

Employment

  • Flutter Developer

    2021 - PRESENT
    OkFuture
    • Refactored an existing app to adhere to clean architecture principles.
    • Introduced various quality assurance tools, like screenshot testing, CI, and code coverage.
    • Implemented new features and released new versions of the Asphaltgold app.
    Technologies: Flutter, Firebase Test Lab, GraphQL, TypeScript, Model View Presenter (MVP), Clean Architecture, Clean Code, APIs

  • Mobile Tech Lead

    2021 - PRESENT
    Ignite
    • Outlined the architecture and implemented open-source tools for mobile app development based on CosmosSDK blockchains.
    • Managed a team of two other mobile developers, mentoring and guiding the direction of the technical aspect of the product.
    • Built a mobile wallet app to manage cryptocurrency assets on the Cosmos Hub blockchain.
    Technologies: Team Leadership, Technical Leadership, Flutter, Firebase Test Lab, Model View Presenter (MVP), Clean Architecture, Clean Code, APIs

  • Mobile Developer (Android + iOS)

    2018 - PRESENT
    Ease (formely EaseCentral)
    • Wrote an Android app from scratch based on the existing iOS version using Kotlin.
    • Refactored the entire iOS application to incorporate clean architecture paradigms and clean code with Swift.
    • Introduced instrumented tests for both Android and iOS using Espresso for Android and EarlGrey + XCUITest for iOS.
    • Integrated Fastlane for an iOS and Android project to help build a working continuous integration solution.
    • Introduced unit tests for both Android and iOS applications.
    • Built custom Gradle scripts to allow easier execution for the continuous integration pipeline of the Android app.
    Technologies: Mobile, Android SDK, Android Testing, Android, iOS, Swift, Kotlin, Test-driven Development (TDD), Xcode, Firebase Test Lab, Model View Presenter (MVP), Clean Architecture, Clean Code, APIs

  • Android Developer

    2020 - 2021
    Groomer.io
    • Developed an Android app for pet grooming shop management.
    • Introduced unit and integration tests using screenshot testing and Espresso framework.
    • Introduced CI/CD services to the development process.
    Technologies: Android, Kotlin, APIs

  • Flutter Developer

    2020 - 2020
    Vid, Inc. (via Toptal)
    • Created video processing functionalities in Flutter, targetting both iOS and Android. Video processing included: Encoding videos, trimming, and applying separate audio streams from the audio files.
    • Introduced new functionalities into the Flutter project as well as existing ones, making sure all of them work well on iOS and Android.
    • Helped the team to promptly deliver the Android counterpart written in Flutter based on the existing iOS native app.
    Technologies: Mobile, Video & Audio Processing, Video Processing, iOS, Android, Videos, Flutter, Test-driven Development (TDD), Firebase Test Lab, Model View Presenter (MVP), APIs, Google Maps API

  • Flutter Developer

    2020 - 2020
    Juno Digital Pte., Ltd. (via Toptal)
    • Created a lottery results app in Flutter from scratch for both Android and iOS.
    • Built a store listing on Google Play and the App Store and conducted the release process.
    • Added crash reporting functionalities with Crashlytics to the Flutter project and monitored the app's performance and health to prevent bad user experience.
    Technologies: Mobile, iOS, Android, Flutter, REST APIs, Test-driven Development (TDD), Firebase Test Lab, Model View Presenter (MVP), APIs

  • Android Developer

    2019 - 2020
    Dubsmash (via Toptal)
    • Introduced new features in a video social media app with over 100 million downloads.
    • Participated in a mature and well-organized scrum process.
    • Helped transition the Java source code into Kotlin.
    • Contributed to the redesign of the outdated user interface.
    • Augmented the current continuous integration setup with custom scripts that automated tedious, repetitive tasks.
    Technologies: Mobile, Android SDK, Android Testing, GraphQL, Kotlin, Android, Firebase Test Lab, Model View Presenter (MVP), APIs

  • Full-stack Android Developer

    2019 - 2019
    Johnson Lab & Supply (via Toptal)
    • Created an Android app that allows field workers to log their work and upload photos and record their exact GPS location.
    • Created an admin panel within the app that requires authentication and authorization. It allows the manager to manage projects and employees and export all collected data to be viewable on the PC.
    • Designed a Firebase database and optimized it for bandwidth usage while keeping the data structure as flat as possible.
    • Introduced the Firestore storage service to allow users to upload files that are referenced in the database and allow for assigning files to certain work items.
    • Introduced Firebase Authentication to allow managers to authenticate when logging into the admin panel.
    Technologies: Cloud Firestore, Mobile, Android SDK, GPS, Firebase Authentication, Firebase Realtime Database, Firebase, Kotlin, Android, REST APIs, Test-driven Development (TDD), Model View Presenter (MVP), Clean Architecture, APIs

  • Senior Android Developer

    2017 - 2018
    Disney Streaming Services
    • Helped build an Android SDK for core functionalities within client apps in an organization, such as authentication, media streaming, and HTTP API communication layer.
    • Maintained and improved Gradle quality plugins related to unit testing and code coverage.
    • Improved the architecture of the SDK to improve testability and mocking for client apps.
    Technologies: Mobile, Android SDK, Android Testing, Kotlin, Android, REST APIs, Model View Presenter (MVP), APIs

  • Android Engineer

    2017 - 2018
    Max2 (via Toptal)
    • Maintained and added new features to an enterprise application for businesses, where venue owners can manage their premises, staff, and client relations.
    • Took care of the continuous integration environment by making sure it was paired up with the code review process.
    • Advised a client with Android-specific decisions about design.
    Technologies: Mobile, Android SDK, Android Testing, Bluetooth, Kotlin, Java, Android, REST APIs, Test-driven Development (TDD), Model View Presenter (MVP), APIs, Google Maps API

  • Senior Android Developer

    2016 - 2017
    Tooploox
    • Introduced continuous integration and continuous delivery to the project.
    • Helped junior developers understand clean architecture and clean code principles.
    • Worked on an Android project for a media industry client from the US.
    • Advised the client about possible solutions for their problems.
    • Provided designs to the design team that adheredf to material design principles.
    Technologies: Cloud Firestore, Mobile, Android SDK, Android Testing, Kotlin, Clean Architecture, Espresso, JUnit, Jira, Jenkins, Java, Android, Scrum, Test-driven Development (TDD), Model View Presenter (MVP), Clean Code, APIs, Google Maps API

  • Lead Android Developer

    2016 - 2016
    X8 Digital Studio
    • Created an Android app for an enterprise client from the UK that helps with networking during different conferences and meetups.
    • Maintained different smaller Android apps within the company.
    • Introduced CI/CD for all the projects under maintenance.
    • Worked closely and directly with the clients to identify their needs and suggest optimal solutions.
    • Refactored apps to work with clean architecture and clean code principles.
    • Incorporated clean code principles into new projects.
    Technologies: Mobile, Android SDK, Android Testing, Espresso, CircleCI, Git, JUnit, Jenkins, Java, Android, Scrum, Model View Presenter (MVP), Clean Architecture, APIs

  • Senior Android Developer

    2013 - 2016
    Ceneo sp. z o.o.
    • Led the Android development team, which consisted of three people.
    • Designed the architecture and implemented an Android app for the biggest price comparison company in Poland.
    • Introduced CI/CD with Atlassian's Bamboo and Jenkins.
    • Wrote UI and unit and integration tests using JUnit and Espresso frameworks.
    • Helped the product owner to identify user needs and plan new features.
    • Guided and taught best practices to new Android developers.
    • Worked on the architecture following a Model–view–presenter (MVP) pattern.
    Technologies: Mobile, Android SDK, Android Testing, Jira, Espresso, JUnit, Bamboo, Jenkins, Java, Android, Objective-C, Model View Presenter (MVP), Clean Architecture, Clean Code, APIs, Google Maps API

Experience

  • Flutter App: Asphaltgold
    https://www.asphaltgold.com/

    EASY PARTICIPATION IN RAFFLES

    Through the Asphaltgold app, you can easily and quickly participate in raffles for the hottest sneakers from Nike, Adidas, New Balance, and many other brands.

    NEVER MISS A THING

    Set up push notifications individually to your desired raffles and be informed automatically and conveniently at the start.

    SECURE AND WITHOUT RISK

    We handle your payment information with the highest level of security. You're always in control of your participation and orders. You can choose between Apple Pay, PayPal, and credit card as your payment method.

    HEAT FOR NEED

    With the app, you also have the option to access our "Heat for Need" category. "Heat for Need" is our in-house charity project which utilizes sneaker hype for a good cause by offering in-demand sneaker models that are already out of stock at an attractive price and donating the difference to the original retail price to changing charities.

  • Library: RESTMock
    https://github.com/andrzejchm/RESTMock

    A library featured in Android Weekly: androidweekly.net/issues/issue-203.

    It includes an HTTP server for Android instrumentation tests, allowing for mocking out HTTP requests and responses in test in a convenient way

  • Android App: Dubsmash

    An app with over 100 million downloads.

    Make lip-sync and dance videos with your favorite music, quotes, and movies! Dubsmash has the world’s largest selection of sounds from your favorite songs, shows, and movies.

  • iOS App: Ease
    https://itunes.apple.com/us/app/ease-formerly-easecentral/id1205766332

    Ease (formerly EaseCentral) is benefits and HR software offered through your company’s insurance broker. It allows the management of time offs and employee benefits as well as approve time-off requests for the manager roles

  • Android App: Ease
    https://play.google.com/store/apps/details?id=com.easecentral.ease

    Ease (formerly EaseCentral) is benefits and HR software offered through your company’s insurance broker. It allows to manage time offs, employee benefits as well as approve time-off requests for the manager roles

  • Android App: Viking App Poland
    https://play.google.com/store/apps/details?id=com.vikingco.vikingapp.poland

    Viking App is the official app for Mobile Vikings mobile network users. It allows for mobile plan management, including recurring payments, checking available balances, buying roaming packages, inviting other users, etc.

  • Android App: Howdy Hub
    https://play.google.com/store/apps/details?id=com.howdyhub.howdy

    Howdy is a way to easily find and connect with relevant people at events and conferences and within "hubs" (communities, clubs, workspaces).

  • Android App: Ceneo
    https://play.google.com/store/apps/details?id=pl.ceneo

    500,000+ downloads

    Android app for the biggest price-comparison portal in Poland.

  • Library: DroidMVP
    https://github.com/andrzejchm/DroidMVP

    Library featured in Android Weekly (http://androidweekly.net/issues/issue-211)

    A small Android library to help you incorporate MVP, passive view, and presentation model patterns in your app.

  • Article: Presentation Model and Passive View in MVP  – The Android Way
    https://medium.com/@andrzejchm/presentation-model-and-passive-view-in-mvp-the-android-way-fdba56a35b1e

    Article featured in Android Weekly (http://androidweekly.net/issues/issue-211)

  • Article: ITDD  –  Instrumentation TDD for Android Using RESTMock
    https://medium.com/@andrzejchm/ittd-instrumentation-ttd-for-android-4894cbb82d37

    Article featured in Android Weekly (http://androidweekly.net/issues/issue-203)

Skills

  • Languages

    Kotlin, Java, Dart, Swift, GraphQL, TypeScript, Objective-C

  • Frameworks

    Flutter, Dagger 2, Android SDK, JUnit, Espresso Testing Framework, Robolectric, Express.js, Swinject

  • Libraries/APIs

    Firebase Android SDK, Retrofit, RxJava, Picasso, REST APIs, Mixpanel Android API, Alamofire, Chai, Google Maps API

  • Tools

    Jira, Android Studio, Crashlytics, Jenkins, CircleCI, Firebase Cloud Messaging (FCM), Bamboo, Fastlane, Xcode, Firebase Test Lab, Firebase Authentication, Gradle, Maven, OneSignal, TeamCity, Mocha, Git, GitHub, Trello, Branch.io, IntelliJ

  • Paradigms

    Model View Presenter (MVP), Test-driven Development (TDD), Scrum, Clean Architecture, Clean Code

  • Platforms

    Mobile, Firebase, Android, iOS, Mixpanel, MacOS

  • Other

    Android Testing, OkHttp, Scrum Master, EventBus, Firebase Cloud Functions, APIs, 3D Printing, 3D Print Design, ESP8266, ESP32, Espresso, Bluetooth, Videos, Video Processing, Video & Audio Processing, GPS, Axios, Team Leadership, Technical Leadership

  • Storage

    SQLite, NoSQL, Firebase Realtime Database, Cloud Firestore

Education

  • Master's Degree in Computer Science
    2009 - 2014
    Wroclaw Univeristy of Technology - Wroclaw, Poland

Certifications

  • React Academy
    SEPTEMBER 2017 - PRESENT
    Toptal, LLC
  • Oracle Certified Associate, Java SE 7 Programmer
    OCTOBER 2014 - PRESENT
    Oracle
  • Professional Scrum Master I
    SEPTEMBER 2014 - PRESENT
    Scrum.org

To view more profiles

Join Toptal
Share it with others
Hire the top 3% of freelance developers TM