Денис

DENYS OLINYK
Ukraine

Android Developer

[open contact info](look above in the "contact info" section) [open contact info](look above in the "contact info" section) https://github.com/disiol

[open contact info](look above in the "contact info" section) https://t.me/Denisimus_IT https://gitlab.com/disiol

SKILLS SUMMARY
Programming Languages: Android developer with 5 years of experience in mobile development, including
C# 1 year dedicated to Android app development. Proficient in Java Core, Android
Java SDK, REST API, SQLite, and Firebase integration.
JavaScript Experienced in Android app architecture, applying clean code principles,
Java SE (Core, OOP, JDBC, design patterns, and SOLID principles. Worked extensively with databases,
IO, Collection) server APIs, payment systems, and analytics integration.
Python (basic) I am looking to apply my expertise in developing fast, secure, and user-friendly
C++(basic) mobile applications in the fintech industry.
Game Engines:
Unity
Unreal Engine EDUCATION
Photon Engine (Multiplayer
Game Development)
National Academy of Security Service of Ukraine
Services: Specialist in Information Security 2007 - 2015
Firebase
Google Maps API
Dagger 2 WORK EXPERIENCE
Zenject
Android Developer | Personal Projects 2023 - Present
REST
AdMob
Unity Ads - Developed an Android application for handling push notifications and
Google Play Services
integrating with Telegram, ensuring instant message delivery and
Web:
improving the user experience.
HTML/CSS
JSON - Built the server-side infrastructure for receiving and distributing messages
OkHttp using Node.js (Express.js) and MySQL, enabling efficient request handling
Retrofit under high loads (up to 1,000 requests per second).
Databases: - Optimized multithreading operations (coroutines, RxJava), reducing
MySQL
memory usage by 28% and increasing app stability.
PostgreSQL
- Implemented MVVM architecture, which accelerated code modification
Testing:
JUnit by 41.5%, improving maintainability and scalability.
Mockito - Developed a message queuing mechanism using Redis and WebSockets,
Version Control: minimizing delivery delays and ensuring reliable data transmission.
Git
Plastic SCM Arb App Pl May 2022 - May 2023
Tools: Unity Developer
IntelliJ IDEA
Responsibilities:
Eclipse Developed over 10 hyper-casual games, achieving 100,000+ downloads across mobile platforms.
Android Studio Implemented a localization system supporting 5 languages, using JSON/XML files and automated resource loading, enabling
seamless international expansion without code modifications.
Other:
Optimized UI animations (Lottie, Spine, Animator), enhancing the user experience and reducing bounce rates by 18.1%.
AR development Analyzed player behavior (Firebase, Game Analytics), leading to a 12% increase in in-app purchase conversion by improving UX/UI.

Firebase integration
Tech Stack: Unity, Firebase, AR, REST, Ads
Android development
Digital Life August 2021 - March 2022
Unity 3D AR Developer
Project Name: Safe Hamsters League
Project Description: A mobile AR game where players control and battle virtual hamsters in an augmented reality
environment. Features multiplayer arena combat and customization options for hamsters
Responsibilities:
Developed a prototype for the AR game Safe Hamsters League, which received positive client feedback
and served as the foundation for the final version.
Built a real-time multiplayer arena system using Firebase, ensuring smooth online battles without lag.
Implemented character customization and integrated 3D model animations, increasing average
session time by 31%.
Optimized project architecture, moving key mechanics to the server, which improved performance and
reduced game latency by 31%.

Tech Stack: Unity, Firebase, AR, REST

Pet project
Unity Developer
Project Name: Liquidator (currently in development)
Project Description: Liquidator is a hyper-casual shooter where the player’s main task is to dodge bombs in a
fast-paced environment. The game features simple mechanics, challenging levels, and intuitive controls,
designed for short and engaging play sessions
Independently developed Liquidator, a hyper-casual shooter with challenging levels and intuitive controls.
Integrated ads and optimized performance for a smooth experience on mobile devices.

Tech Stack: Unity, Firebase, Ads, AR
GitLab Link | YouTube Demo

LANGUAGES
English – Upper-Intermediate
Ukrainian – Native