Dmitry Guselnikov, Developer in Yerevan, Armenia
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Dmitry Guselnikov

Verified Expert  in Engineering

Software Developer

Yerevan, Armenia
Toptal Member Since
February 2, 2017

Dmitry is an Android developer with ten years of experience. He holds a specialist’s degree from the National Research University of Electronic Technology in Moscow and has worked on mass media, medical, and fintech projects as an app developer. Dmitry is a moderate perfectionist and focuses on problem-solving.


Idobi (via Toptal)
Model View ViewModel (MVVM), Data Binding, Kotlin, Android...
Naneos (via Toptal)
Model View ViewModel (MVVM), Java, Android, Firebase Cloud Messaging (FCM)
Delovaya Sreda by Sberbank
Android, Firebase Cloud Messaging (FCM), Figma




Preferred Environment

IntelliJ IDEA, Git, MacOS

The most amazing...

...projects I've built are a Yarus POS-terminal,, and

Work Experience

Android Developer

2019 - 2021
Idobi (via Toptal)
  • Created the second version of the app for Idobi Radio.
  • Designed the app architecture using MVVM, Repositories, and Dagger.
  • Implemented the video player with ExoPlayer custom UI.
  • Added the radio player with on-screen and notification controls.
  • Administered an XML documents parser for client-server interaction.
Technologies: Model View ViewModel (MVVM), Data Binding, Kotlin, Android, Firebase Cloud Messaging (FCM)

Android Developer

2020 - 2020
Naneos (via Toptal)
  • Refactored the existing app and corrected live data interaction with data binding.
  • Corrected the app architecture, specifically MVVM and LiveData, UI bindings, and repositories.
  • Analyzed the app for memory leaks, fixed crashes, and increased stability.
  • Corrected the app styles according to the Material design guidelines.
  • Created a live data chart showing real-time air pollution.
Technologies: Model View ViewModel (MVVM), Java, Android, Firebase Cloud Messaging (FCM)

Android developer

2017 - 2019
Delovaya Sreda by Sberbank
  • Developed an app in collaboration with team members (
  • Implemented UI for carousel cards.
  • Implemented HLS video content playback.
  • Designed the app architecture.
  • Implemented the 120s section with short business life hack videos.
Technologies: Android, Firebase Cloud Messaging (FCM), Figma

Android Developer

2017 - 2018
  • Developed a social trading app in a team using Java and Kotlin.
  • Created a widget set that meets the requirements of design code.
  • Wrote unit and integration tests.
Technologies: GitLab, Kotlin, Java, Firebase Cloud Messaging (FCM), Figma

Android Developer

2017 - 2017
AdGate Media (via Toptal)
  • Built an SDK for developers who want to integrate ads by AdGate Media to their Android apps.
  • Implemented downloading, storing, and playing video ads.
  • Created a log system that helps developers debug the integration.
  • Supported implementation of web offer wall ads.
Technologies: Gradle, Android Support Library, Android, Java, Firebase Cloud Messaging (FCM)

Android Developer

2016 - 2017
  • Wrote an Android app that connects to a bracelet and processes received data.
  • Designed a REST API for the server.
  • Implemented server-client interactions, including continuous synchronization.
  • Implemented collecting and exchanging of ECG data.
Technologies: GitLab, Git, REST, Bluetooth LE, Bluetooth, Android, Firebase Cloud Messaging (FCM)

Android Developer

2014 - 2016
Genome Ventures
  • Developed Android apps for projects called APIO and Otvet.
  • Designed a server REST API.
  • Implemented IM for Android based on websockets.
  • Designed architecture for Android, iOS apps, and back end.
Technologies: Bitbucket, Git, OkHttp, Realm, Android Studio, Android SDK, Firebase Cloud Messaging (FCM)

Android Developer

2013 - 2014
Media Storm
  • Developed UI for Rustoria and Android apps.
  • Developed client-server interaction.
  • Designed a version-based server API.
  • Implemented a switchover to a new version of the API. Moved from RPC to REST.
Technologies: Realm, REST APIs, Android SDK, Firebase Cloud Messaging (FCM)

Android Developer

2011 - 2012
  • Wrote an Android client for Trassir CCTV.
  • Implemented hardware-accelerated video streaming for H.264 format (via RTSP).
  • Implemented video frame rendering using OpenGL ES 2.0.
  • Implemented stream decoding using FFmpeg.
  • Created integration with native code (written in C and C++) using Android NDK and JNI technologies.
Technologies: OpenGL, Android NDK, Android SDK, C++, C, Java, Firebase Cloud Messaging (FCM)

C/C++ Developer

2009 - 2011
Terminal Technologies, Ltd.
  • Wrote programmer-friendly wrappers for POS terminal component drivers.
  • Supported YARUS POS app developers who used Yarus API.
  • Developed a Yarus launcher for apps.
  • Integrated Boost library (smart pointers, collections).
  • Implemented installing apps onto a POS terminal based on XML candidate (manifest) files.
Technologies: Subversion (SVN), C++, C, Linux, Firebase Cloud Messaging (FCM)

APIO Clubs

Apio is a platform for creating and managing private clubs. Private clubs are private discussion communities for privileged members. One can be a member of multiple clubs at the same time. The clubs may be joined only by invitation; this approach supports regular users.

Otvet App

Smart business messenger where everyone can convert a chat message to a task and assign it to any member of the team.
2007 - 2012

Specialist's Degree in Computer Science

National Research University of Electronic Technology - Moscow


REST APIs, Android Support Library, Retrofit, JSON-RPC, Retrofit 2, RxJava, Firebase Android SDK, OpenGL, Butterknife


Bitbucket, Git, Android Studio, Android NDK, GitLab CI/CD, Firebase Cloud Messaging (FCM), IntelliJ IDEA, Subversion (SVN), Gradle, GitHub, GitLab, Figma


Android SDK, Flutter, AngularJS, Dagger 2


Kotlin, Java, Python, HTML5, CSS3, JavaScript, C, C++, Swift, Objective-C, PHP, GraphQL


Model View ViewModel (MVVM), REST, Scrum, Test-driven Development (TDD)


Android, MacOS, iOS, Linux, Firebase, Bluetooth LE, Windows


Realm, MySQL


OkHttp, Bluetooth, Data Binding

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