Gabriel Gircenko, Software Developer in Zagreb, Croatia
Gabriel Gircenko

Software Developer in Zagreb, Croatia

Member since March 11, 2014
Gabriel has worked as a developer specializing in Android software for the past six years. He has worked on multimillion-dollar user apps, he is passionate about proper development processes, and he knows how to foster them. He prefers Kotlin over Java and Flutter over Kotlin. Lately, he has immersed himself in AR/VR, 3D, and even 4D projects. Gabriel communicates exceptionally well and has been on teams of all sizes.
Gabriel is now available for hire


  • Epigraph
    Scrum, Google Play Store, Android Studio, Android SDK, Git, Gradle, Firebase...
  • Minds+Assembly
    Scrum, Android Studio, Android SDK, User Experience (UX), Git, Gradle, ARCore...
  • Idyllic
    Android Studio, Android SDK, OWASP, Java, Android



Zagreb, Croatia



Preferred Environment

Scrum, Jira, Android, Model View Viewmodel (MVVM), Android SDK, Git, Kotlin, Android Studio

The most amazing...

...project I've built from scratch to deployment was an Android app, which I also maintained with updates.


  • Owner | Android Consultant

    2014 - PRESENT
    • Founded a company to get more reliable job opportunities.
    • Built three apps from scratch and managed them until deployment.
    • Managed, led, and taught two developers successfully.
    • Learned about business in general i.e., how to build and how to grow one.
    • Helped clients reach their goals and deadlines every time.
    Technologies: Scrum, Google Play Store, Android Studio, Android SDK, Git, Gradle, Firebase, Parse, REST, Java, Android
  • Android Senior Engineer

    2019 - 2019
    • Worked as an Android lead engineer with Minds+Assembly in a five-person team.
    • Another Android Developer and Gabriel replaced the previous developer and were in charge of finish the Android app on a tight deadline schedule.
    • Developed his first commercial app with Kotlin and ARCore library.
    • Built custom controllers which utilize only a drag gesture to successfully interact with an object in 3D space.
    • Animated multiple VR/AR objects moving on a click.
    • Increased the knowledge of the technology tremendously over the course of the project to make this possible.
    Technologies: Scrum, Android Studio, Android SDK, User Experience (UX), Git, Gradle, ARCore, Kotlin, Android
  • Android Senior Engineer

    2019 - 2019
    • Documented extensively all the details in a simple 15 page Google Doc file which made the client extremely happy.
    • Wrote a few suggestions based on OWASP Android security guidelines.
    • Suggested Kotlin to replace Java.
    • Chose technologies for the client e.g., Chrome over WebView because the Chrome web browser is safer from hackers.
    • Overcame a clunkily built UI (no usage of dimensions, styles, and unnecessary usage of text sizes) by fixing UI bugs and making design suggestions; the client was very satisfied with the document.
    Technologies: Android Studio, Android SDK, OWASP, Java, Android
  • Senior Android Engineer

    2016 - 2018
    • Developed two apps from scratch and worked on them as the only Android developer.
    • Implemented beta testing with HockeyApp crash reporting.
    • Used a 3D library called LibGDX for demonstrating and interacting with 3D models.
    • Implemented fresh changes for three complex screens without damaging any of the previous functionality.
    • Used Retrofit for all the REST requests.
    • Used a Picasso library for image handling.
    • Implemented a chat and in-app and real-time notifications with Firebase.
    Technologies: Scrum, Google Play Store, Model View Presenter (MVP), Push Notifications, Android Studio, Android SDK, User Experience (UX), Java, Google Cloud Messaging, Firebase, 3D, LibGDX, HockeyApp, Git, REST, Google Maps, Android
  • Android Senior Engineer

    2015 - 2016
    • Developed two premium video-content-streaming apps with millions of users and their library.
    • Made improvement suggestions of which 90% were adopted.
    • Learned about VIPER, architecture variation in MVP, and worked in TDD with Mockito and PowerMockito tests.
    • Worked on a variety of tasks, as needed: caching, fixing bugs, making improvements (UI, memory, code), sending tracking data, writing tests, changing models according to JSON responses, and more.
    • Worked with five people on a daily basis in a team of more than 20 people.
    Technologies: Scrum, Unit Testing, Model View Viewmodel (MVVM), Jira, Android Studio, Android SDK, Java, Git, Mockito, Test-driven Development (TDD), Android


  • HBO GO (Development)

    I developed two premium content-streaming Android applications and their libraries. My most significant contribution was making the UI code more robust. Until then, there had been more than two bug fixes per week on the UI. After that, we changed the UI only if the specifications changed.

    Technologies: Android, TDD, Java, Mockito, PowerMockito

  • Onfido | Identity Verification SDK (Development)

    I was in charge of implementing a screen reader accessibility feature from scratch. Working there was one of my best work experiences.

    Technologies: Kotlin, Bitrise, GitLab

  • Jumprope | How-to Videos (Development)

    I was in charge of bug fixing and implementing new features.

    Technologies used: Kotlin, Fastlane, CircleCI, AWS, Firebase

  • Beformance (Development)

    This app is a personalized weight-loss program. I worked as an only Android developer alongside an iOS developer.

    Technologies: AndroidX, MVP, Dagger 2, RxJava

  • Player FM (Development)

    Most of my work on this project consisted of updating the UI and implementing Android Wear API for an urgent release of the podcast application. This was my first Kanban project, made in Android Studio, and hosted on GitHub.

    Technologies: Android, Android Wear

  • Vimvest | Organized Investment Goals (Development)

    Alongside two Android senior developers, I learned a lot about Android and successfully developed with it.

    Technologies: AndroidX, Kotlin, Dagger 2, Coroutines

  • The Top App for Mothers (Development)

    I worked on this mother-targeted app that ranked #1 for downloads in its country. I co-developed the Android version from scratch and was mainly in charge of the UI. Delivering the required customization made this a fun project.

    Technologies: Android, Analytics

  • TAKH Tutor AR (Development)

    TAKH Tutor AR is an AR/VR app that educates patients about their healthcare products.

    I was the lead Android engineer using Minds+Assembly in a five-person team. I also worked closely with an in-house iOS developer and a 3D designer to match the experience. Another Android developer and I were in charge of finishing the Android app within tight deadlines.

    Project Highlights:
    • Developed my first commercial app with Kotlin and ARCore library.
    • Built custom controllers that utilize only a drag gesture to successfully interact with an object in 3D space.
    • Animated multiple VR/AR objects that moved on a click. I increased my knowledge of the technology tremendously over the course of the project to make this possible.

  • FYX Driver (Development)

    I worked as the sole senior Android engineer building an MVP of the app from scratch to publish, and I was in charge of publishing updates. This was one of two enterprise apps I developed for FocustApps.

    Technologies: Android, Google Maps, REST, Git, HockeyApp, libGDX (3D), Firebase, Google Cloud Messaging

  • Crorex | MT4 Developer (Development)

    I was in charge of developing a hedging algorithm in MQL4. 90% of direction guesses are successfully closed in profit. Now, I'm in charge of adding new features to the same EA.

  • FYX Mechanic (Development)

    I was the sole senior Android engineer building the MVP of this app from scratch and publishing it along with updates. This was one of the two enterprise apps I developed for FocustApps.

    Technologies: Android, Google Maps, REST, Git, HockeyApp, LibGDX (3D), Firebase, Google Cloud Messaging

  • Idyllic | Identity App and Code Review (Development)

    Idyllic was in a pre-investment stage, and they needed a well-documented code review. In one week, I wrote more than 20 pages in a Google Doc file with a heavy emphasis on security. In addition to the in-depth security review, I also gave code improvement suggestions, composed bug reports, and gave design improvement according to Android design guidelines.

  • Droidcon Zagreb 2015 | Publication (Other amazing things)

    I delivered a speech titled "From Android Beginner to a 5-star Freelancer." This was my first professional talk, and I enjoyed speaking and sharing my knowledge about freelance work. After the speech, I obtained one business deal and a few developers approached me for a job, which was great.

    The link attached is an article written about the talk (in Croatian).

  • TaxiCentral (Development)

    I co-founded the TaxiCentral startup. Our goal was to make a super easy-to-use app for people who want to order a taxi in Zagreb. Basically, it was the Uber for taxi companies.

    I was responsible for the full development and the rollout, and everything in between—working on the architecture, documentation, partial design, testing, publishing, and promotion. This was my first published application.

    Technologies: Android

  • LandKeeper | Hackathon (Other amazing things)

    I developed the Android part while my college peers implemented the web crawling for this project. We won first place and received other perks like free office space for a year. The link attached is our pitch for the project (in Croatian).

  • BookBottles | Management (Development)

    BookBottles helps nightclubs easily manage reservations, table inventory, guest lists, client profiles, and transactions. On this project, I implemented the communication between the client and our developer.

  • Dir po Zagrebu (Development)

    For this project, I built an Android app from scratch with a Parse-based back end for a pub-crawling brand. I also set up everything so the founders could easily add events to the Parse back end.

    Technologies: Android, Parse

  • Xpatpub (Development)

    The client’s goal was to publish an Android pub-crawling app to the Google Play Store. They chose me to develop it after I gave a review of the two previous developers' code.

    I implemented the full development of the Android and Parse back end, completing the weekly tasks I had brainstormed with the client. I also migrated the app from Eclipse to Android Studio and the back end from DreamFactory to Parse.

    Technologies: Android, DreamFactory, Parse, Facebook Integration

  • Conference App for Dubai (Development)

    The client's goal was to complete a partially (70%) completed app. They had previously employed four freelance developers who each, in turn, did some work before moving on. The code was in terrible condition and the client had a very tight schedule.

    I worked on the UI changes, database, and REST API without improving the code because of the tight schedule and limited budget. The client delivered a fully developed app on time.

    Technologies: Android, SQLite

  • Insighter | Management (Development)

    For Insigter, I managed the project using Trello in the idea stage and then moved it to the Bitbucket issue list. I also led two Android developers, added Facebook likes and Twitter followers, and fixed several bugs.

    Technologies: Android, Material Design Library, Social Media Integration

  • Moviez | Management (Development)

    I managed the development of a social media app that would make movie recommendations. Eventually, we discontinued the project because it lacked a good monetization strategy.


  • Languages

    Java, Kotlin, XML, MQL4, JavaScript, Swift, GraphQL
  • Frameworks

    Android SDK, Flutter, LibGDX, Mockito, Dagger 2, Dagger, Ruby on Rails 5, React Native, JUnit
  • Libraries/APIs

    Google Maps API (GeoJSON), Google Maps, Google Maps Geocoding API, Retrofit, Google Maps API, Facebook API, Twitter API, RxJava, RxJava 2
  • Tools

    Trello, Android Studio, Git, GitLab, Jira, GitHub, Slack, Google Docs, Google Sheets, Google Cloud Console, Gradle, Asana, Google Cloud Messaging, Android Jetpack, Basecamp, Unity 5, WiX, Firebase Cloud Messaging (FCM), Photoshop CC, GitLab CI/CD
  • Paradigms

    Model View Presenter (MVP), REST, Kanban, Model View Viewmodel (MVVM), Scrum, Agile, Dependency Injection, Waterfall Development, Model View Intent (MVI), Model View Controller (MVC), Test-driven Development (TDD), Unit Testing, Testing
  • Platforms

    HockeyApp, Android, Firebase, ARCore, WordPress, iOS, Parse, Bitrise
  • Storage

    SQLite, JSON
  • Other

    User Experience (UX), User Interface (UI), Mobile GPS, SDKs, Google Drive, Android Animations, Push Notifications, Location Services, Lifecycle-aware Components, Slack App, Architecture, Agile Sprints, Google Material Design, Google Play Store, OWASP, Squarespace, InVision App, Coroutines

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