Android Developer
2022 - 2022HypeLabs (via Toptal)- Developed an Android SDK in Java for creating mesh networks via BLE for facilitating internet transactions by devices with limited connectivity.
- Implemented device disappearance and internet connectivity state propagation via a mesh network.
- Stabilized the Java codebase by improving its thread safety.
Technologies: Android, Java, Bluetooth LE, Mesh Networking, Java Concurrency, Concurrent ProgrammingAndroid Developer
2020 - 2021Stilling- Created an app that allows technicians to find a car's model from the catalog or its license plate and then order parts for it.
- Supervised the work of an intern developer who covered the project with tests and added some new functionality.
- Integrated the Phrase service to maintain the app's translation into more than 10 languages.
- Created an app for Zebra tablet that is able to scan products' barcodes and make an order via the shop's API.
Technologies: Kotlin, Android, Model View Viewmodel (MVVM), Coroutines, SVG, Android Material Design, Zebra EMDK, Barcode Reader, Phrase, Trello, Mobile Development, REST APIsAndroid Developer
2019 - 2021PrivateWifi- Developed an app in Kotlin from the ground up that changes the client's DNS address and demonstrates the data compression capabilities of the company's service by playing YouTube videos.
- Maintained an SDK for making apps that connect to the company's VPN.
- Maintained documentation for the above-mentioned SDK's API.
- Refactored the source code for an app that helps to reduce users' mobile traffic.
- Debugged and added new functionality for different flavors (brandings) of the company's Android app for connecting to their VPN based on network conditions—mobile data, secure and insecure WiFi.
- Updated the apps' target API level to meet the requirements of Google Play.
Technologies: Android, Java, Kotlin, VPN, Git, Phabricator, Robospice, Debugging, Flavors, Gradle, WorkManager API, EventBus, Model View Viewmodel (MVVM), Widgets, Mobile DevelopmentAndroid Developer
2019 - 2020Starlink Pharma SAS (via Toptal)- Added a few features (including barcode scanning functionality) to an existing Android app.
Technologies: Java, Kotlin, Android, Mobile DevelopmentKotlin Android Developer
2018 - 2019Momentstudios- Added new features to two existing Android apps.
- Incorporated Jetpack libraries into project.
- Integrated dependency injection framework (Dagger2).
- Helped to migrate from Realm to RoomDB.
Technologies: RxJava, RoomDB, Model View Viewmodel (MVVM), GraphQL, Kotlin, Android, Mobile DevelopmentFreelance Android Developer with Strong Cryptography Experience
2018 - 2018NDA Client (via Toptal)- Implemented an Android app from the groundup to deal with Ethereum transactions.
Technologies: AES, QR Codes, Cryptocurrency, Ethereum, Web3.js, Kotlin, Android, Mobile DevelopmentFreelance Android Developer
2018 - 2018Rehash, LLC (via Toptal)- Created custom Android component (Draft.js editor) for React Native.
- Fixed bugs in a React Native app.
Technologies: Draft.js, Android, JavaScript, Kotlin, Java, React Native, Mobile DevelopmentFreelance Mobile App Developer
2018 - 2018POMCO (via Toptal)- Refactored an Android app.
- Updated the UI and added animations.
- Improved reliability of the Bluetooth connection.
- Added support for the newest Android versions.
Technologies: Bluetooth, Android Data Binding, Android, Java, Mobile DevelopmentFreelance Android Developer
2018 - 2018Codecacao (via Toptal)- Enhanced and supported the existing Android app.
Technologies: Android, Kotlin, Mobile DevelopmentAndroid Developer
2017 - 2018NearGroup- Supported an Android messenger app.
- Fixed chat latency and connection reliability issues.
Technologies: Mongoose, XMPP, Java, Android, Mobile DevelopmentAndroid Developer
2017 - 2017UP Project Developments- Developed a voice recorder from scratch.
- Built a simple Material Design UI.
- Facilitated the auto sending of recorded files via SMTP.
Technologies: SMTP, Audio Recording, Java 8, Rx, Reactive Programming, Android, Mobile DevelopmentFreelance JavaScript Expert
2017 - 2017MICA (via Toptal)- Supported user scripts for automating work with Google Spreadsheets.
- Added new features using GAS.
Technologies: Spreadsheets, Google Apps Script, JavaScript, Google SheetsAndroid Developer
2017 - 2017Confidential Company- Supported an Android client app with embedded photo taking and recognition.
Technologies: Model View Presenter (MVP), DBFlow, Retrofit, Android Camera App, RxJava 2, Android Data Binding, Android, Mobile DevelopmentFreelance Android Developer
2016 - 2017BioMetrix (via Toptal)- Created an Android app (from scratch) that communicated with peripheral devices via Bluetooth.
- Contributed to the creation of the UX and design for the app.
- Implemented a time-synchronization protocol with a 10-millisecond precision.
- Implemented BT communication data recovery logic.
Technologies: Animated GIFs, Amazon Web Services (AWS), Retrofit, Bluetooth, Android, Mobile DevelopmentAndroid Developer
2016 - 2016Yalos- Supported an Android app that shows funny animated reminders about missed calls, events, emails, IMs, and more.
Technologies: Accessibility, Android, Mobile DevelopmentAndroid Developer
2016 - 2016Cong- Created an Android mobile client application for a playlist management web-service.
- Implemented a custom design.
Technologies: Realm, Audio Streaming, Android, Mobile DevelopmentFreelance Android Developper
2016 - 2016Uprise (via Toptal)- Created an Android app for data visualization from scratch.
- Used a chart graphical library to display data from weather stations.
Technologies: Android, Java, Mobile DevelopmentFreelance Android Developer
2016 - 2016MCProHosting (via Toptal)- Fixed bugs and added a new functionality to an Android client for viewing live streams.
- Added RTMP video-streaming support.
- Changed the existing UI to make it compliant with the material design.
- Helped to integrate the app with Google Cast.
Technologies: Real-time Messaging Protocol (RTMP), HTTP Live Streaming (HLS), Video Streaming, WebSockets, Android, Java, Mobile DevelopmentAndroid Java Developer
2015 - 2015Jank Studios- Developed a social media app for Android.
- Integrated Facebook, Twitter, and Instagram networks into the app.
Technologies: Instagram, Twitter, Facebook, JSON, REST, Java, Android, Mobile DevelopmentAndroid Java Developer
2015 - 2015Raul Marco (Private Customer)- Created an app for picking assigned locations for your contacts on your Android device.
Technologies: SQLite, Java SE, Android, Mobile DevelopmentAndroid Java Developer
2015 - 2015ActiveHealth- Added modifications to an existing open-source Android app to change its behavior.
- Redesigned the brand for the above mentioned app.
Technologies: HTML Parsing, Java SE, Android, Mobile DevelopmentPhoneGap Developer
2015 - 2015Yevhen Teneta (Private Customer)- Created a prototype of an animated audio-book reader app for Android and iOS using PhoneGap.
Technologies: CSS, JavaScript, HTML5, Cordova, PhoneGap, Mobile DevelopmentJava Developer
2012 - 2015ELEKS Software- Developed a web app that manages cloud computers from AWS; this involved using J2EE/Spring stack for the back end and HTML/JavaScript/CSS for the front end.
- Created a mobile app for contacting people inside a company using Scala for Android.
- Supported an Android time-tracking app using Java and SQLite.
- Built an Android market-type app using Java and implementing Material Design.
- Maintained and tested PDF-rendering component of a web-service using Java.
- Supported a Blackberry legacy time-tracking project using J2ME.
Technologies: Amazon Web Services (AWS), Mercurial, Scala, JPA, Bootstrap, jQuery, Ajax, CSS, JavaScript, HTML, EclipseLink, Spring, Java EE, ORMLite, SQLite, Java SE, Android, Mobile DevelopmentJava Mobile Developer | Lua Developer
2011 - 2012GlobalLogic- Developed a smart-card emulator for Blackberry smartphones using Java ME.
- Created a UI framework for TV applications with Lua script.
- Built a testing framework using Lua.
- Wrote unit tests for a framework running in an embedded system.
- Developed the UI and business logic for a native Android app related to video processing.
- Debugged and modified a Bouncy Castle library for working with cryptographic entities.
- Created a video-player demo application with Lua scripting.
Technologies: Subversion (SVN), Lua, Android, PKCS, BlackBerry, Java ME, Java SE, Mobile Development