Luka is available for hire

Luka Velimirovic

Verified Expert in Engineering

Software Developer

Location

Belgrade, Serbia

Toptal Member Since

October 19, 2016

Luka is an Android developer with more than five years of experience who started his professional work during his software engineering studies and Microsoft internship. Since then, he has worked in a number of teams of various sizes. While Android is his primary focus, he is interested in all things technical and has experience working with web services using technologies like Node.js and Java EE.

Windows Agile Software Development Android Git Android API Android SDK Android Studio SourceTree Retrofit JSON Kotlin Java MacOS Butterknife SQL

Portfolio

Universal Tennis LLC

Android, Kotlin, Material Design, SQL, Espresso, Git, Flow, Coroutines...

Vuclip

State Machines, Android Jetpack, Coroutines, Kotlin...

We Help You GmbH

Android SDK, Java, Android Architecture Components, Kotlin, Android...

Experience

Android - 8 years Git - 8 years Java - 5 years Kotlin - 5 years Jira - 4 years Firebase - 4 years Android Jetpack - 3 years MongoDB - 1 year

Availability

Part-time

Preferred Environment

Git, IntelliJ IDEA, Android Studio, MacOS

The most amazing...

...work I've coded is a photo editing feature which allows users to add text, stickers, or draw freehand on photos they take, similar to stories on Instagram.

Work Experience

Android Engineer

2021 - PRESENT

Universal Tennis LLC

Took over the app's development, leading a team of two to deliver before the deadline.
Tracked and fixed bugs using Jira, Firebase, and Bitbucket while reviewing pull requests to ensure code quality and stability of the app.
Collaborated closely with QA to deliver weekly app updates after the initial release.

Technologies: Android, Kotlin, Material Design, SQL, Espresso, Git, Flow, Coroutines, Retrofit 2, Dagger 2, RxJava

Android Architect

2018 - 2020

Vuclip

Restructured the entire codebase of an application that serves more than 50 million users.
Developed a framework for writing Android apps based on state machines and Google's Jetpack libraries.
Provided a framework with flexible high-level features, reducing boilerplate code to a minimum and fulfilling the client's needs.
Performed a high number of UI optimizations so that the app could be installed on a lot of lower-end devices.

Technologies: State Machines, Android Jetpack, Coroutines, Kotlin, Android Architecture Components, Android SDK, Android, Android Studio, Firebase, Design Patterns, Object-oriented Programming (OOP), SourceTree, Dagger 2, Agile Software Development, Android API, SQL, JSON

Android Developer

2017 - 2018

We Help You GmbH

Developed an app called Weyvee from scratch and solo, using the latest technologies in the Android ecosystem. The app targets high school and undergraduate students and allows them to post weyves that are similar to tweets, only anonymously.
Implemented a picture editing feature for the Weyvee app that allows users to draw freehand, add text, and add stickers to the pictures they take. This feature is similar to what other apps like Instagram offer with their stories.
Updated an old app, called Abihome, with a range of features like unified registration and login system that works together with Weyvee; it also has an invitation feature allowing users to invite their schoolmates to use Abihome and Weyvee with them.

Technologies: Android SDK, Java, Android Architecture Components, Kotlin, Android, Android Studio, Retrofit, Design Patterns, Object-oriented Programming (OOP), SourceTree, Dagger 2, Windows, Android API, SQL, JSON

Android Developer

2016 - 2017

Collide

Set up an MVP code structure with an industry-standard tech stack at that time.
Developed and optimized all of the custom UI elements.
Worked on a messaging functionality using Twilio SDK.
Developed a live-streaming client with chat functionality.
Wrote JUnit tests covering most of the business logic.

Technologies: Android SDK, Java, Kotlin, Android, Android Studio, Retrofit, Design Patterns, Object-oriented Programming (OOP), SourceTree, RxJava, Windows, Agile Software Development, Android API, JSON

Android Developer

2014 - 2016

Kudos Ltd.

Worked on Fly Launcher—an Android launcher, a stock launcher replacement on Android phones, creating a bottom circular toolbox, booster app with booster widget, clock widget, and more.
Wrote a casting functionality library for Chromecast that supports videos, images, and audio tracks with controls like pause, play, rewind, and more.
Wrote a Caster SDK, a wrapper for Cast libraries; these are variations on the Chromecast library that provide a similar functionality only for different devices, like Amazon Fire Stick and Roku.
Worked with an FFmpeg transcoding library to transcode videos in real time that is used before casting videos to Chromecast, for example. Since Chromecast supports only a couple of formats, this library transcodes to one of the supported, primarily MP4.
Developed a custom Android Ad SDK whose structure is similar to Google's AdMob or Appnext SDK.

Technologies: Python, Android SDK, Java, Android, Android Studio, Butterknife, Retrofit, Design Patterns, Object-oriented Programming (OOP), SourceTree, Dagger 2, Windows, Agile Software Development, Android API, SQL, JSON

Intern

2013 - 2014

Microsoft

Worked on a subproject for the Microsoft Office Sway app, participating in an internship program.
Integrated an Azure Cloud SDK into the application.
Learned from local industry leaders how to setup projects and work with teams of different sizes.

Technologies: C#, .NET, Azure, Design Patterns, Object-oriented Programming (OOP), Windows, JSON

Experience

Viu — Korean Dramas, Variety Shows, Originals

https://play.google.com/store/apps/details?id=com.vuclip.viu

A Kotlin-based app similar to Netflix but with content mainly from India, Indonesia, and Korea. There was already a version of this app on the Google Play Store, but the client needed features that couldn't be integrated into the existing monolithic codebase. So I created a framework that one team, myself included, used to rewrite the whole app from scratch, introducing newly requested features into it as well.

Weyvee

https://play.google.com/store/apps/details?id=de.wehelpyou.weyvee

An app that enables German students to post "weyvee" which is similar to tweeting but anonymous. Weyvee be commented on and liked, and as more action happens around the weyvee, the user's school receives points and rises in the ranking. With this app, they also can manipulate and post images.

Collide

Collide is a streaming app that lets celebrities connect to their fans. Fans can watch live streams, buy photos and videos, and also chat with or call celebrities of their choice. This app is present on Google Play, and it also has an iOS version alongside the web app.

BitX Torrent Streaming

This is a Torrent streaming app. It allows you to watch media from torrents without downloading them completely first. Other distinguishable features include transcoding videos in real-time into a format supported by your device, and it also automatically finds and downloads subtitles.

Megacast

This is a Chromecast casting app. It can be used to cast videos, music, and images from your Android to a Chromecast device. It supports most media formats; some are natively supported by Chromecast, and others are transcoded on the fly using FFmpeg library. The transcoding feature separates this app from other similar apps on Google Play.

Fly Launcher

This was my first project for Kudos Ltd. It is an Android launcher and serves as a stock launcher replacement on Android phones. I was one of two developers that worked on this project.

I developed the following:
• Bottom circular toolbox
• Booster app with booster widget
• Clock widget
• Search feature switch to RxJava
• Other code features

simpliTV

A client app that allows users to watch television channels offered by simpliTV in Austria. It has a feature where you can rewatch media that is two days old, list channels through an EPG grid, and more.

Body Builder

http://slideme.org/application/body-builder

This is one of the first apps that I developed in my spare time. It is an app for people interested in bodybuilding and a healthy lifestyle. It has a step counter, a BMI calculator, an expandable database of foods used to track calories, a database of exercises with images and descriptions of how to perform them, and more.

OffersRings SDK

I have led a team of two to develop a custom Android ad network SDK. Android developers can use this SDK to incorporate ads into their apps, similarly to the Appnext SDK or Google's AdMob. This SDK offers native ads, along with prepared widgets like the AppWall.

ReachOut

A social app that helps users who are battling with depression or some physical sickness. A user can share his experience via a status similar to Facebook, and other people can comment on it or send them direct messages.

Sway App

https://sway.com/

I worked on a subproject for the Microsoft Office Sway app as a part of the internship program. It also involved integrating the Azure Cloud SDK into the application and overall analysis of the code structure and improvement where it was needed.

Skills

Languages

Kotlin, Java, SQL, Python, C#

Frameworks

Android SDK, Dagger 2, Jersey, Express.js, .NET, Espresso

Libraries/APIs

Android Architecture Components, Butterknife, Android API, Retrofit, RxJava, Node.js, Retrofit 2

Tools

Android Jetpack, Git, SourceTree, Android Studio, Asana, Jira, RxAndroid, Gradle, IntelliJ IDEA, Flow

Paradigms

Agile Software Development, Design Patterns, Object-oriented Programming (OOP)

Platforms

Android, Windows, MacOS, Firebase, Azure, Linux, Fedora

Storage

JSON, RoomDB, MongoDB, NoSQL, MySQL, Realm

Other

Mobile App Development, Coroutines, State Machines, Material Design

Education

2015 - 2017

Master's Degree in Software Engineering

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

2011 - 2015

Bachelor's Degree in Software Engineering

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

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