Zsolt Safrany, Developer in Budapest, Hungary
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Zsolt Safrany

Verified Expert  in Engineering

Software Developer

Budapest, Hungary
Toptal Member Since
July 7, 2014

An enthusiastic Android developer, Zsolt has brought a number of apps to life and published them to the Google Play Store. Possessing a Master's degree in Computer Science, he has solid Enterprise Java experience in multinational environments and speaks English fluently.


Component Soft
Android, Java
Humble Engineering
Google App Engine, Java, Android
JavaScript, HTML, EPUB, Eclipse, Git, SQLite, Java, Android




Preferred Environment

OS X, Git, IntelliJ IDEA, Android Studio

The most amazing...

...thing I've done is code an Android app providing a curated collection of 20k+ public domain books, spreading knowledge and learning to everyone for free.

Work Experience


2012 - PRESENT
Component Soft
  • Worked as an Android and Java instructor.
  • Created course materials such as slides and exercises.
Technologies: Android, Java


2011 - PRESENT
Humble Engineering
  • Founded Humble Engineering, a side project whose goal is to create fun and awesome apps.
  • Developed a number of Android apps, which are accessible at http://goo.gl/4xuU4m.
Technologies: Google App Engine, Java, Android

Head of Android Development

2012 - 2013
  • Created Free Books for Android, an app that makes more than 20,000 classic books and audiobooks available to users at no cost.
  • Implemented a WebView-based EPUB renderer with paging and bookmarking to display books.
  • Introduced multi-level caching of book cover images to improve UX and save bandwidth.
  • Implemented JSON-based server communication to fetch social metadata of books (e.g. comments, ratings).
  • Created a sophisticated audiobook chapter downloader. The downloader was planned and built with ambitious (and conflicting) goals in mind: it should prefetch chapters so that users never have to wait, it should be lazy to save bandwidth and battery, it should be aware of remaining available free disk space, it should never slow down the device (i.e. it should have a limit on maximum simultaneous downloads) and also consider whether or not the user is connected via a metered internet connection.
  • Implemented an audiobook chapter player with custom UI elements.
  • Integrated Google Play In-app Billing.
  • Integrated crash reporters, analytics, and ad networks like BugSense, KISSmetrics, Flurry and Mobclix.
  • Created a small app that sends live Photoshop mockups to a physical Android device to make designers more productive.
Technologies: JavaScript, HTML, EPUB, Eclipse, Git, SQLite, Java, Android

Senior Java Developer

2010 - 2010
Qualysoft Hungary
  • Developed a web-based information system application, available to the clients of Uniqa CZ.
  • Integrated the web application with different heterogeneous Uniqa services.
Technologies: Eclipse, CVS, JAX-WS, Apache Velocity, Spring, RichFaces, JSF, WebSphere, Java

Enterprise Java Architect

2008 - 2010
Lufthansa Systems Hungary
  • Architected the Integrated Operations Control Center Platform.
  • Maintained, refined, and advanced the architectural concept of our platform.
  • Provided technical specifications for sub-projects and work packages.
  • Defined and completed work packages.
  • Ensured compliance with configuration and build management.
  • Defined and implemented test cases.
  • Provided estimates for change requests.
  • Reported progress to sub-project manager.
Technologies: Eclipse, Apache Maven, Hibernate, JMS, JPA, Enterprise Java Beans (EJB), Spring, JBoss, Java

Java Developer

2007 - 2008
AltaCom Ltd.
  • Developed a cell phone-based traffic information system in the Java EE environment.
Technologies: JavaScript, CSS, Apache Tomcat, Servlet, Jakarta Server Pages (JSP), MySQL, Java

Free Books

Boasting handpicked collections, the app allows users to quickly download an unlimited number of classics and read them anywhere with a modern and easy-to-use interface. As the exclusive app programmer, I worked with our dedicated UI designer to implement the desired app interface.

The Preview

One of the great perks we had at Spreadsong is our "hack week". During one of those events, I created a small app to make designers more productive. The Preview is a fast and easy way to send Photoshop mockups live to an actual Android device. This makes designing an app's interface much easier, since a potential design can be immediately previewed on a physical device.

Carrot - Shopping List

Carrot is a simple and easy-to-use shopping list app. Although I'm not a designer, I am always searching for the best UX when writing an app (once a clean and functional code base is established). This app reflects my standpoint that less is more, both with regard to implementing a clean UI without unnecessary bells and whistles and writing a concise app description in Play Store.

App Engine Dashboard

As a big fan of the Google Cloud Platform, when I realized that only a web-based (i.e. non-native) dashboard exists for Google App Engine I immediately decided to create a great app that developers can use to monitor GAE-hosted applications on their Android device. It was quite challenging because there is no public API for accessing dashboard data, so I needed to scrape everything (via regex) from the web pages.

Humble Bubbles Live Wallpaper

Interactive bubbles as an Android Live Wallpaper. Nothing more, nothing less.

Guide the Sheep

The game tells the story of some lovely sheep and a dog that takes care of them. Playing as the dog, your job is to guide those sheep through the environment with special care. This is my only app that never got completed, since it was too ambitious. I did all the coding and two of my friends created the art for the game.

Don't Mind the Mine

Don't Mind the Mine is an inverse minesweeper, meaning that instead of avoiding mines you have to find and collect them all. This was the very first Android app that I created, more than three years ago. This app shows that a mobile app is never "done" or "completed", since mobile platforms are constantly evolving and UI patterns keep changing. The app could really use a complete revamp - I wish I had the time for it!


Needle is an open-source, simple but powerful multithreading library for Android.

APNS Library for Google App Engine

This is an open-source, Java library specifically designed to work on Google App Engine. It makes sending push notifications to iOS devices via Apple Push Notification Service simple and easy.


Java, SQL, HTML, CSS, JavaScript


Android SDK, Oracle ADF, OpenXava, JUnit, Spring, JPA, Hibernate, JSF, Apache Velocity, Jakarta Server Pages (JSP)


Eclipse IDE, Android Studio, WaveMaker, Apache Sling, Apache Maven, CVS, Servlet, Apache Tomcat, IntelliJ IDEA, Gradle, Git


Object-oriented Programming (OOP), Clean Code, REST, Model View Controller (MVC)


Parse, Android, Java EE, Google App Engine, Eclipse, JBoss, WebSphere, OS X


SQLite, JSON, Google Cloud Datastore, MySQL


Takes, EPUB, Enterprise Java Beans (EJB)


Butterknife, Retrofit, Picasso, Guava, JMS, RichFaces, JAX-WS, Google+ API, Facebook API

2003 - 2008

Master's Degree in Computer Science

Budapest University of Technology and Economics - Hungary

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