Gabriel Gircenko, Software Developer in Zagreb, Croatia
Gabriel Gircenko

Software Developer in Zagreb, Croatia

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




Zagreb, Croatia



Preferred Environment

Android Studio, Kotlin, Git

The most amazing...

...project I've ever built was an Android app which I built from scratch to deployment and continued maintaining it 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: Android, Java, REST, Parse, Firebase, Gradle, Git
  • 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: Android, Kotlin, ARCore, Gradle
  • 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, Java, OWASP
  • 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: Android, Google Maps, REST, Git, HockeyApp, LibGDX (3D), Firebase, Google Cloud Messaging
  • Android Senior Engineer

    2015 - 2016
    Digital Media Experience
    • Developed two premium video-content-streaming apps with millions of users and the library for those.
    • Made improvement suggestions of which 90% were adopted.
    • Learned about VIPER, architecture variation in MVP, 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: Android, Mockito, PowerMockito, Git


  • Premium Content Streaming Application (Development)

    I developed two premium content-streaming Android applications and their library. This application has millions of users across the world. The most significant thing I've done 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 only changed the UI if the specifications changed.

    Technologies: Android, Java, Mockito, PowerMockito

  • TAKH Tutor AR (Development)

    TAKH Tutor AR is an AR/VR app for educating the patients about their healthcare product.

    I worked as an Android lead engineer with Minds+Sssembly in a five-person team. I also worked closely with an in-house iOS developer to match the experience and a 3D designer. Another Android developer and I were in charge of finishing the Android app on a tight deadline schedule.

    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.)

  • RoadStar (Development)

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

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

  • The Top App for Mothers (Development)

    I worked on this mother-targeted app that was also #1 for downloads in its country. I specifically developed the Android version from scratch with another developer and was mainly in charge of the UI part. This was the most fun I had because of the various customization I needed to do.

    Technologies: Android, Analytics

  • Live Streaming Coding Sessions (Other amazing things)

    Recently I've started live-streaming my coding for fun sessions and it has been an amazing experience - learning, sharing knowledge with viewers and most importantly, keeping each other accountable and productive.

    I'm streaming professional project only if the client asks for it.

  • MechanicStar (Development)

    I was the sole senior Android engineer building the MVP of the app from scratch and publishing it along with the new updates. This is one of the two enterprise apps I did 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 gave 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 on freelance work. After the speech, I obtained one business deal and a few developers who came up to 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 startup, TaxiCentral. Our goal was to make a super easy-to-use app for people who want to order a taxi in Zagreb. Basically, the Uber for taxi companies.

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

    Technologies: Android

  • PlayerFM (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

  • 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 with a Parse-based back-end from scratch for a pub-crawling brand. In addition, I set up everything so the founders could easily add the events to the Parse back-end.

    Technologies: Android, Parse

  • Xpatpub (Development)

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

    On this project, I implemented the full development of the Android and Parse back-end, doing the weekly tasks that 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 wanted the completion of a partially completed app (70%). They had previously employed four freelance developers; who, one after another, all worked on it a bit and then bailed 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 budget limitations. The client ended up delivering a fully developed app on time.

    Technologies: Android, SQLite

  • Insighter | Management (Development)

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

    Technologies: Android, Material Design Library, Social Media Integration

  • Moviez | Management (Development)

    Moviez is a social media app that makes movie recommendations and on this project, I managed the development. Eventually, we discontinued the development because of a lack of a good monetization strategy.


  • Languages

    Java, Kotlin, XML, GraphQL, Dart, Swift, C#
  • Frameworks

    Android SDK, LibGDX, Mockito, Flutter, JUnit, React Native, Unity
  • Libraries/APIs

    Google Maps API (GeoJSON), Google Maps, Google Maps Geocoding API, Retrofit, Google Maps API, Facebook API, Twitter API, Node.js
  • Tools

    Trello, Android Studio, Git, Eclipse IDE, GitLab, Jira, GitHub, Slack, Google Docs, Google Sheets, Google Cloud Console, Gradle, Asana, Flutter SDK
  • Paradigms

    REST, Kanban, Model View Presenter (MVP), Scrum, Agile, Waterfall Development, Model View Intent (MVI), Model View Viewmodel (MVVM), Model View Controller (MVC)
  • Platforms

    Android, HockeyApp, Firebase, ARCore, Parse
  • Storage

    SQLite, JSON
  • Other

    Agile Sprints, Google Material Design, Google Play Store, OWASP

To view more profiles

Join Toptal
I really like this profile
Share it with others