Semir Zahirovic, Developer in Sarajevo, Federation of Bosnia and Herzegovina, Bosnia and Herzegovina
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Semir Zahirovic

Verified Expert  in Engineering

Software Developer

Sarajevo, Federation of Bosnia and Herzegovina, Bosnia and Herzegovina
Toptal Member Since
December 17, 2015

Semir is a professional Android and Java developer. He has worked on the design and implementation of advanced Android apps, done bug fixing, and worked with third-party libraries to ensure the best performance and features. He communicates well and is willing to work until his code is perfect.



Preferred Environment

Xcode, Android Studio, iOS, Android

The most amazing...

...thing I've worked on was a project that involved fast rendering optimization and mobile payments

Work Experience

Android Developer

2014 - 2016
  • Constructed a complete payments module using Stripe, and an instant chat app that had a custom gallery upload option.
  • Maintained the offline data persistence and two-way data synchronization.
  • Optimized networking and rendering performance.
  • Provided the back-end and cloud support.
  • Implemented Google Maps and Mapbox integration.
  • Redesigned the user interface for applications using the latest trends and technologies.
  • Accelerated the development of the new Android development stack using the latest tools and approaches.
  • Created custom animations for loaders, hiding cells, action bars, and others.
Technologies: RxJava, Fabric, EventBus, Picasso, Parse, Realm, Android SDK, Java


2012 - 2015
University of Sarajevo, Faculty of Electrical Engineering
  • Implemented simple Android applications with local storage using MySQL database, that are consuming information provided from a REST API.
  • Created REST APIs from design to implementation.
  • Created reusable components for Android SDK to improve view rendering and performances.
  • Designed an application based on Google best practices.
  • Wrote unit tests and implemented them for the Android platform.
Technologies: Java, Android

I acted as the senior Android engineer for this project.

Tasks accomplished:
• Worked in a scrum environment.
• Drastically improved code and testing quality.
• Implemented multi-modular horizontal architecture for different features of the application.

Daily Highlights

I developed a Tinder-like app (an easy-to-use mobile dating app) for another company. I made my own swipeable fast-rendering cards that are supported on every Android device made in the last four years. I used hardware support to enable fast rendering.

There are two million users currently using this application for the management of their teams.

I created my own network communication layer to support the communication with the API. I implemented Stripe payments for the mobile platforms. As this is a large project, I implemented custom animations to improve the UX, used a ViewHolder pattern to improve the UX when scrolling, and used for data caching. Android SDK
I developed an Android SDK which collects data about memory usage, CPU usage, and monitors network calls and device data. The SDK has a low memory footprint and the performance of the application was not degraded by the extensive data collection of the SDK.

Politiken Books (via Toptal)

I redesigned UI of the app and implemented a lot of custom UI components to support great UX. It allowed HLS (HTTP live streaming) streaming of audio books and enabled the user to save and play them from segments saved in a cache. Implemented custom ebooks text and highlighting. Also implemented and added support for streaming/playing audio sources on Google Cast devices.

Vital Health (via Toptal)

I developed a simple video-chat application using a WebRTC SDK for Android.

Grassroot (via Toptal)

I implemented the full offline mode for the existing application by using a queue system, job schedulers, and enabled a two-way data sync between local and remote databases. I also enhanced the application performance by using a multi-threading environment in combination with and RxJava. In addition, I created the generic error handling and generic IO methods by using

StartShield Launcher (via Toptal)

I have drastically improved the performances of Android launcher. I created new transitions and animations and restructured the code so it can support easier development.


GraphQL, Kotlin, SQL, Java, Swift, C++, C, JavaScript


Dagger 2, Mockito, JUnit, Android SDK


RxJava 2, Retrofit 2, GCM, RxJava, Butterknife, StickyListHeaders, Picasso, Google Maps SDK, Firebase Android SDK, Protobuf, Stripe API, Facebook API, Fabric, PubNub


Android, Firebase, Parse, iOS


Realm, RoomDB


Firebase Cloud Messaging (FCM), ExoPlayer, Android Studio, Xcode, Sketch


Agile Software Development, Scrum, Model View Viewmodel (MVVM), Model View Presenter (MVP)


Multithreading, SOLID Principles, Optimization, EventBus, Offline Data Synchronization

2013 - 2015

Master of Science Degree in Electrical Engineering

University of Sarajevo - Sarajevo, Bosnia and Herzegovina

2010 - 2013

Bachelor of Science Degree in Telecommunications

University of Sarajevo - Sarajevo, Bosnia and Herzegovina

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