Djuro Gluvajic, Developer in Belgrade, Serbia
Djuro is available for hire
Hire Djuro

Djuro Gluvajic

Verified Expert  in Engineering

Bio

Djuro is an engineer and developer with extensive experience providing various types of solutions, including game engines, OCR engines, computer graphics, business solutions, and tools both for desktop and web. He is both passionate and skilled in his development work.

Portfolio

DMJC, LLC
Android, Kotlin, Jetpack Compose, SDKs, JitPack, GitHub...
Givelify LLC
Android, Kotlin, Agile, Jira, Java, BrowserStack, Continuous Integration (CI)...
Kesko Senukai Digital UAB
Java, Dagger, Android, Android SDK, Firebase, Agile, Monday.com, RxJava, SDKs...

Experience

  • C++ - 17 years
  • Microsoft Visual Studio - 15 years
  • Java - 11 years
  • Android - 5 years
  • C# - 5 years
  • ADT - 3 years
  • Kotlin - 2 years
  • Windows Presentation Foundation (WPF) - 2 years

Availability

Part-time

Preferred Environment

Visual Studio, NetBeans, Android Studio

The most amazing...

...thing to see is the first smile of a child testing a "Hugo" game.

Work Experience

Senior Android Developer

2023 - 2024
DMJC, LLC
  • Developed and maintained an SDK for advertisement experience improvement from the beginning to multiple releases, following rules of clean architecture and clean code.
  • Developed an Android test app on how to use the SDK.
  • Wrote tests for the SDK to improve the quality of delivery.
  • Set up a Gitflow development process and enforced it for the team, preparing for continuous integration.
  • Provided consultations to the team on improving the design and architecture of the SDK while also giving Android-specific insights.
  • Assisted the partner company in making the 1st successful integration of the SDK to a top-five Play Store sound-playing app.
  • Used Jira and Linear to handle the project's Agile process.
  • Wrote documentation explaining how to use the Android SDK and elements of the SDK.
Technologies: Android, Kotlin, Jetpack Compose, SDKs, JitPack, GitHub, Continuous Integration (CI), Java, Clean Code, Clean Architecture, VAST, Jira, Linear, Mobile Architecture, User Interface (UI), Crashlytics, APIs, Android App Design

Senior Android Developer

2022 - 2023
Givelify LLC
  • Redesigned the whole Android project from Activity and ContentView architecture to clean architecture with MVVM.
  • Migrated code to new architecture without breaking any current functionality, adding new features and fixing bugs.
  • Redesigned and coded Bitrise workflows and GitHub Actions to Gitflow while adding required unit testing and reviews to necessary branches.
  • Added many new unit tests to the project. Added test coverage reports in the project. Increased test coverage from 0 to 20%.
  • Consulted designer teams on the execution time of required design and possible alternative solutions to save development time before and after the tickets were finalized.
  • Consulted the management team on issues that could arise from the current code before they could scale into bigger problems.
  • Added documentation in Confluence for Android architecture, the GitHub flow, Bitrise flow, etc.
  • Created a Postman workspace adding REST API calls needed for Android development.
  • Improved QA teams by teaching them how to use tools such as Postman, but also giving them new test cases.
Technologies: Android, Kotlin, Agile, Jira, Java, BrowserStack, Continuous Integration (CI), Continuous Delivery (CD), Bitrise, Android Studio, Unit Testing, GitHub, GitHub Actions, Kodein, Clean Architecture, Dependency Injection, Slack, Automated Testing, Git Flow, Card Payments, Payment Security, PCI Compliance, Firebase, Firebase Android SDK, Crashlytics, CleverTap, MURAL, Confluence, Android Jetpack, Mobile Development, Mobile Apps, Mobile Applications, Mobile Architecture, User Interface (UI), APIs, Android App Design

Senior Android Developer

2021 - 2022
Kesko Senukai Digital UAB
  • Maintained multiple international retail apps in various foreign languages.
  • Consulted with the company to improve its project development process.
  • Used continuous integration to check style, test and build apps, and upload them to Firebase.
  • Refactored most of the Android apps to use LiveData and data binding.
  • Added multiple new retail features and consulted with the management on the UX.
  • Transformed resource items from their raw format to a vector format.
  • Consulted the company on improving the management process to gain more results from developers in less time.
Technologies: Java, Dagger, Android, Android SDK, Firebase, Agile, Monday.com, RxJava, SDKs, Urban Airship, Material Design, LiveData, Android Jetpack, Mobile Development, Mobile Apps, Mobile Applications, Mobile Architecture, User Interface (UI), Crashlytics, APIs, Android App Design

Senior Android Developer

2020 - 2021
Belk (via Toptal)
  • Administered a top 50 US goods selling app in 2020.
  • Moved a big codebase from Java to Kotlin, and changed the code to be more Kotlin-like.
  • Implemented JUnit and instrumental tests to cover over 80% of the app.
  • Used continuous integration for a safer development environment.
  • Added several new features to the app for different types of sales and shipments.
  • Implemented various deep links and generic deep link handling for the app, including Branch, Facebook, and third-party deep links.
  • Redesigned multiple parts of the app to be more UX-friendly.
  • Consulted the design and managing team on Android UX.
Technologies: Java, Kotlin, RxKotlin, Push Notifications, Silent Push Notifications, REST APIs, Agile, Third-party Libraries, Third-party Frameworks, Zeplin, Jira, Figma, Android, Android SDK, Firebase Android SDK, Adobe Analytics, Firebase Analytics, Firebase Crashlytics, Android Jetpack, Mobile Development, Mobile Apps, Mobile Applications, Mobile Architecture, User Interface (UI), Firebase, Crashlytics, GraphQL, APIs, Android App Design

Android Developer

2019 - 2020
Switch Four, LLC
  • Worked in a team on maintaining and improving an existing app.
  • Converted parts of the app from MVP to MVVM with LiveData.
  • Added over 50 new screens with many custom views, including customizing Android drawables.
  • Worked in cooperation with the testing team to write documentation and improve testing.
  • Added deep links, Dynamic Links, AppLink, and notification handling.
  • Improved app stability and performance by finding edge cases, creating better architecture, and creating unit tests.
  • Consulted on design and features to improve the user experience and user interface for Android (UI/UX).
Technologies: Continuous Integration (CI), Git, Slack, Postman, Clubhouse, LiveData, Model View Presenter (MVP), Model View ViewModel (MVVM), REST, Retrofit, Dagger 2, Room, Java, Kotlin, Android, Android Jetpack, Mobile Development, Mobile Apps, Mobile Applications, Mobile Architecture, User Interface (UI), Firebase, Crashlytics, APIs, Android App Design

Android Developer

2018 - 2018
Moova
  • Created an MVP for a delivery service app named MOOVA.
Technologies: RxJava, Kotlin, Android, Android Jetpack, Mobile Development, Mobile Apps, Mobile Applications, Mobile Architecture, User Interface (UI), Firebase, Crashlytics, APIs, Android App Design

Android Developer

2018 - 2018
Moss
  • Created an app from start to delivery for calling a quasi-elevator on a building spot.
Technologies: Amazon Web Services (AWS), Java, Android, Android Jetpack, Mobile Development, Mobile Apps, Mobile Applications, Mobile Architecture, User Interface (UI), Firebase, Crashlytics, APIs, Android App Design

Android Developer

2016 - 2018
Dynamicare
  • Developed an Android app from scratch with multiple releases on Google Play. Its services are in separate processes that work and connect to the app when it opens or closes, and it uses location services with Geofence in parallel to connect.
  • Connected the existing app to React Native and created a specific part of the app using this technology.
  • Created classes that could communicate with a measuring device using BLE technology.
  • Developed classes that would enable using a measuring device by analyzing the sound coming from a 3.5mm stereo jack.
  • Created classes for recording various videos and uploading them to the server.
  • Created custom views.
Technologies: JUnit, Material Design, React Native, FogBugz, Clubhouse, Realm, Pure Data, REST, Android, Android Jetpack, Mobile Development, Mobile Apps, Mobile Applications, Mobile Architecture, User Interface (UI), Firebase, Crashlytics, APIs, Android App Design

Android Developer, Consulting

2015 - 2016
Tangent Solutions
  • Created an Android app for recognizing trees. Optimized a big database for Android size requirements for an app (FlySAA) that must work in conditions without connectivity.
  • Created an Android app called Zapper for comunicating through an open accessory with a custom POS device. Created a protocol for communication with the open accessory.
  • Created an Android app called Beagle for handling Beacons.
  • Created FlySAA, an Android app for organizing and tracking flights for South Africa Airlines.
  • Worked with an iOS team to make multiple apps user-friendly for both platforms.
  • Consulted the management for many solutions.
Technologies: Android Open Accessory (AOA), FTDI, Bluetooth Beacons, Bluetooth Low Energy (LE), REST, Android, Android Jetpack, Mobile Development, Mobile Apps, Mobile Applications, Mobile Architecture, User Interface (UI), Firebase, APIs, Android App Design

Android Developer

2015 - 2015
Blend Systems, Inc.
  • Created an Android app for a social network.
  • Created a custom camera control for Android.
Technologies: Android, Java, Android Jetpack, Mobile Development, Mobile Apps, Mobile Applications, Mobile Architecture, User Interface (UI), Firebase, APIs, Android App Design

Developer

2014 - 2015
Petcom
  • Contributed to the development of a POS service for bars, hotels, and restaurants using a MVVM WPF.
  • Created modules for designing bar/restaurant rooms, for dynamic multilevel report creation/printing and for document creation.
  • Designed the database and parts of the software.
  • Trained programmers in MVVM WPF.
Technologies: Windows Presentation Foundation (WPF), C#, User Interface (UI), APIs

Team Leader, Developer

2007 - 2014
TCOM Belgrade
  • Created a 360° view virtual walk system using Adobe Flash (see www.gorski.rs).
  • Created small educational games for children on Android (mathematics, language, etc.).
  • Designed a system for reading electrical meters using Android devices and a web app to prepare/analyze data for/from the Android app.
  • Created a specific OCR for reading electric meters.
  • Created the Android app for reading electric meters using Android Development Tolls and Eclipse.
  • Coordinated the creation and customization of web apps for the Flash utility using a simple scripting tool.
  • Coordinated and created parts of the web app for managing the reading of the electrical devices using PHP, JavaScript, MySQL, and FTP.
  • Created various server services using Java.
Technologies: MySQL, C#, JavaScript, PHP, Android SDK, Java, C++, Flash, Mobile Development, Mobile Apps, Mobile Applications, Android, User Interface (UI), APIs, Android App Design

Developer, Team Leader

2005 - 2006
Apotekarska Ustanova Beograd Cooperation with Europos
  • Coordinated the customer experience with project creation.
  • Coded various parts of the database for financial handling using MS SQL.
  • Led a team of 22 people (hardware people, software people, and drivers).
  • Designed several parts of the software for POS terminals.
  • Created an ISDN communication service using Visual C++ (in order to do database replication through telephone lines—required limitations in communications between distant units).
  • Educated over 1300 pharmacists to use the software within 1 month and used their suggestions to improve the software.
Technologies: Microsoft Visual C++, Microsoft SQL Server, APIs

Developer

2002 - 2004
TCOM Belgrade
  • Created games using Java Applets.
  • Created tools for handling finances in a business Visual C++.
  • Developed tools for POS terminals.
  • Developed tools for handling fiscal printers using C++.
  • Created desktop applications for managing trading companies using Visual C++ and MS SQL.
Technologies: Microsoft Visual C++, Microsoft SQL Server, User Interface (UI), APIs

Developer, R&D Programmer

2000 - 2001
Interactive Television Denmark
  • Developed a small game alone on the ITE game engine.
  • Developed a demo game with a small team.
  • Created a 2D collision system using C++.
  • Built a 3D engine using Visual C++ in the R&D team.
  • Programmed a MIDI sound system for Playstation using C++.
  • Created a particle system for Playstation using C++ and Assembler.
  • Scripted several character models using the ITE game scripting tool.
Technologies: DirectX, C++, PlayStation, User Interface (UI), APIs

Experience

Hugo

https://en.wikipedia.org/wiki/Hugo_(video_game)
The game that hit the world like a truck on TV, PC, Amiga, and Playstation.

360 Virtual Walk System

An engine made in Flash used on several websites.

System for Managing a Pharmaceutical Company

I worked for the Europos when making the software for Apoteke Beograda, the biggest pharmaceutical company in Serbia. It was made in 2005 and it is still used to this day in a chain of 105 pharmacies, five labs, and managing units.

VSS ORD

http://www.tcom.rs/
A software that serves to read electrical meters in Serbia with an OCR, GPS tracking, and other services.

It is currently used to measure to measure 3,000,000 units every month in Serbia.

Blend

An app for a social network.

Worked on a custom camera control, custom picture management, and custom gallery.

FlySaa

Created a complete Android App for South African Airlines. It helps users to book, track and view flights.

It will soon be on the Google Play Store.

Dynamicare

https://play.google.com/store/apps/details?id=com.dynamicarehealth.rewards&hl=en
An Android app for helping people recover from addiction, which was developed from start with several Google Play updates.

TRIVA

An Android app to help people get to the right floor on a building spot using a buck hoist.

Moova

An Android MVP app for a delivery service.

Worktrip

Worked in a team on adding new features and maintaining an
app for organizing events.

Education

1993 - 2003

Bachelor's Degree in Computer Science

University of Belgrade, School of Electrical Engineering - Belgrade, Serbia

Certifications

OCTOBER 2023 - PRESENT

Flutter BLoC - From Zero to Hero Complete Course

Udemy

OCTOBER 2023 - PRESENT

The Complete Flutter Development Bootcamp with Dart

Udemy

Skills

Libraries/APIs

REST APIs, RxKotlin, RxJava 2, RxJava, Firebase Android SDK, DirectX, Retrofit, LiveData

Tools

Clubhouse, FogBugz, Microsoft Visual Studio, Android Studio, ADT, Gradle, GitHub, Crashlytics, Android Jetpack, Flash, Adobe Creative Suite, Eclipse IDE, Postman, Visual Studio, Microsoft Visual C++, Slack, Git, Zeplin, Jira, Figma, Adobe Analytics, Firebase Analytics, BrowserStack, Kodein, Confluence

Languages

Kotlin, Java, Assembler, SQL, C++, C#, GraphQL, PHP, HTML, JavaScript

Frameworks

Android SDK, Windows Presentation Foundation (WPF), JUnit, Dagger 2, React Native, Dagger

Paradigms

Agile, REST, Mobile Development, Unit Testing, Model View ViewModel (MVVM), Model View Presenter (MVP), Dependency Injection, Continuous Integration (CI), Continuous Delivery (CD), Clean Architecture, Automated Testing, Clean Code

Platforms

Mobile, Firebase, Android, Windows, NetBeans, Bitrise, PlayStation, Bluetooth Low Energy (LE), Amazon Web Services (AWS), CleverTap

Storage

SQLite, Microsoft SQL Server, FileZilla FTP Server, MySQL, Realm

Other

Location Services, Location Tracking, Mobile GPS, SDKs, Push Notifications, Silent Push Notifications, Android App Design, User Experience (UX), User Interface (UI), Software, Mobile App Development, Mobile Apps, Mobile Applications, Jetpack Compose, Mobile Architecture, APIs, Android Animations, Android Open Accessory (AOA), GitHub Actions, Bluetooth Beacons, Pure Data, Material Design, Room, FTDI, Third-party Libraries, Third-party Frameworks, Firebase Crashlytics, Monday.com, Urban Airship, Git Flow, Card Payments, Payment Security, PCI Compliance, MURAL, Computer Science, JitPack, VAST, Linear

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring