Andrew Abakumov, Developer in Istanbul, Turkey
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Andrew Abakumov

Verified Expert  in Engineering

Android Developer

Istanbul, Turkey
Toptal Member Since
June 11, 2021

Andrew is a senior Android developer who started out with Java at a global telecommunications company. After the first smartphones appeared, he saw the power and potential of mobile apps and switched his focus to Android. Andrew now has a decade of Android expertise under his belt, with in-depth knowledge of cloud storage, email, instant messaging, and marketplace apps. A professional highlight of Andrew's is developing an in-app instant messenger Android app with over ten million downloads.


Android, Kotlin, REST, REST APIs
Kotlin Multiplatform, GLSL, WebGL, OpenGL ES
Remontnik, LLC
Android, Java, Kotlin, Retrofit, Room, SQLite, WebSockets, REST APIs




Preferred Environment

Linux, IntelliJ IDEA, Android Studio, Android SDK, Java, Kotlin, Git, Jetpack Compose

The most amazing... storage Android app I've built is for Yandex: the disk reminded users of Dropbox, but they liked it much more, and it had superior ratings on Google Play.

Work Experience

Expert Android Developer

2021 - PRESENT
  • Developed two mobile Android Apps for Customers of Android.
  • Developed medical services app for school students and their families; more information can be found at
  • Developed a health and wellness app for medical services and remote therapeutics, specifically personalized virtual care; more information can be found at
Technologies: Android, Kotlin, REST, REST APIs

Kotlin Multiplatform Developer

2020 - 2022
  • Developed my own multiplatform 3D game engine using Kotlin Multiplatform, which runs on Android, iOS, desktop, and the web.
  • Remade a good-old arcade billiard game using my 3D game engine; more information can be found at
  • Created an MVP of 3D interior design software—covering floors, walls, doors, windows, furniture, and walls; it was built using my own 3D engine and developed with Kotlin Multiplatform.
Technologies: Kotlin Multiplatform, GLSL, WebGL, OpenGL ES

Senior Android Developer

2015 - 2021
Remontnik, LLC
  • Developed an Android marketplace app for building and repairing services.
  • Developed in-app messenger for a custom WebSocket API.
  • Integrated third-party payment systems for services payments.
  • Set-up continuous integration with GitLab CI for building and test running.
  • Developed a filling and validation tool that also sent forms with complicated business logic.
  • Managed a team of two internal developers and with one outsourcing developer.
Technologies: Android, Java, Kotlin, Retrofit, Room, SQLite, WebSockets, REST APIs

Android Application Developer

2015 - 2015
  • Developed my own Android project from scratch (both coding and design).
  • Created a camera app with colorful effects and real-time previews.
  • Reimplemented graphical effects processing from CPU to GPU (using OpenGL ES), that resulted in high FPS increase.
Technologies: Android, Java, OpenGL ES, Kotlin Multiplatform, Camera API, REST APIs

Android Applications Developer

2011 - 2014
  • Developed Android apps for email, instant messaging and cloud storage.
  • Created a WebDAV protocol client with custom extensions.
  • Developed parsing for the custom binary protocol of a cloud storage app.
  • Initiated file and directory synchronization with a remote source for an Android cloud storage app.
  • Refactored legacy code to make it much more readable and efficient.
  • Developed an XMPP protocol client with custom extensions.
  • Delivered certain parts of the account manager (common component for the company's Android apps).
Technologies: Android, Java, WebDAV, XML, JSON, WebView, SQLite, REST APIs, XML Parsing

Software Developer

2007 - 2010
  • Developed integrations with client's web services using Java, WSDL, and custom XML protocols.
  • Built Servlets and JavaServer Pages (JSP) pages for product configuration.
  • Developed code generation tools for internal company usage.
  • Implemented business logic for workflow via specifications using Java and Oracle SQL, PL/SQL.
Technologies: Java, WebLogic, Oracle, SQL, REST APIs, XML Parsing

Yandex.Disk — Cloud Storage App
A cloud storage Android application for documents, photos, videos and other files with automatic background synchronization of data. I was one of the key developers and together we created this fast app with great user experience and high Google Play ratings.

A fast and reliable email client with an in-app instant messenger Android application. I ported the legacy code from a J2ME project and refactored it to be more readable and suitable for the Android platform. Now it has more than ten million installs.

Sine Pariwar — Healthcare App
A healthcare mobile Android app for school students and their families, which provides simple access to medical services like therapeutics, medical analysis, connection with school doctors, and making an appointment with a doctor.

Resolute — Personal Healthcare Services
A mobile Android app for health and wellness service for personalized virtual care.

It had a remote video connection with a care team feature: that includes doctors, nurses, and health coaches.

It allowed users to make appointments for medical analysis and doctors.

Lead Android Developer

I developed a camera surveillance app for Android. This app uses a smartphone as a camera and a server for video storage and hosts the web console inside a local area network. The web console can provide real-time video surveillance, motion detection, and playback of motion recordings.
2004 - 2010

Master's Degree in Applied Mathematics, Physics, and Informatics

Moscow Institute of Physics and Technology (MIPT) - Moscow, Russia


REST APIs, Camera API, OpenGL ES, Retrofit, WebGL


Git, Android Jetpack, IntelliJ IDEA, Android Studio, WebView


Android SDK


Java, Kotlin, XML, SQL, GLSL


Android, Linux, Oracle


SQLite, XML Parsing, JSON




Numerical Modeling, Numerical Simulations, 3D Math, WebSockets, Coroutines, Physical Science, WebLogic, WebDAV, XMPP, Room, Jetpack Compose, Kotlin Multiplatform

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