Stefan Nikolov, Developer in Rousse, Bulgaria
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Stefan Nikolov

Verified Expert  in Engineering

Debugging Developer

Rousse, Bulgaria
Toptal Member Since
May 23, 2016

Stefan is a talented software engineer with over 5 years of professional experience in mobile games development (from porting, to creation, to team lead) and 10 years as back- and front-end web developer (from the earliest HTML+ASP to PHP5+MySQL+JavaScript+jQuery now)


Knowledge Based Intelligence
jQuery, JavaScript, MySQL, PHP
SAP IDoc, HIPAA Electronic Data Interchange (EDI), Subversion (SVN), Oracle SQL...




Preferred Environment

Apache HTTP Server, Git, TortoiseSVN, Visual Studio

The most amazing...

...thing I've developed is an accelerometer-driven music app for iOS with own low-latency sound mixer and compressor.

Work Experience

Open-Source Software Developer

2015 - 2016
  • Designed and developed the Behave3d library, a JavaScript library for dynamic behavior and animations of HTML elements.
  • Wrote complete documentation+examples of the library, available on a site which itself is a demonstration of the library's functionality (
Technologies: JavaScript

Web Developer

2010 - 2015
Knowledge Based Intelligence
  • Designed, developed, and supported a corporate training and testing system “Knowledge Based Intelligence,” used internally at Alliance Boots GmbH production sites in the UK.
Technologies: jQuery, JavaScript, MySQL, PHP

Software Consultant

2010 - 2010
  • Consulted for corporate clients on electronic document standards and their technical implementation on various networks (AS2, HTTP, IPX400, Tradanet, etc.). Wrote XSL transformations for different electronic data interchange formats (EDI, MRT, IDOC,…).
Technologies: SAP IDoc, HIPAA Electronic Data Interchange (EDI), Subversion (SVN), Oracle SQL, XSLT, XML

iOS Developer

2009 - 2010
  • Developed accelerometer-driven music applications.
  • Published titles YossBeats and YossGuitar.
  • Researched and developed gesture recognition via accelerometer data.
  • Developed a sound mixer + compressor achieving the lowest possible latency on an iOS device for playing (simultaneous) sounds, not using the standard API sound mixing.
Technologies: C++, Objective-C, Xcode, Adobe Photoshop, 3ds Max, OpenGL ES

Mobile Games Developer

2005 - 2009
  • Ported the program for the King Kong project. Technologies used: C, BREW on Visual Studio; SVN.
  • Ported the program for Platinum Solitare, Real Football 2007, Rayman 3, Gameloft Backgammon, Midnight Bowling, and Mystery Mansion Pinball projects. Technologies used: J2ME on JBuilder, Eclipse, SVN, Perl, and Python.
  • Created code for Diamond Rush, Rayman Kart, and The Settlers projects. Technologies used: J2ME on JBuilder, XML via DocumentBuilderFactory, SVN.
  • Led the development of CSI: Miami (iPod), Brothers in Arms: Hour of Heroes (iPhone), and Rise Of Lost Empires (iPhone) projects. Technologies used: C++ and ObjectiveC on Visual Studio and XCode, OpenGL ES, iPhone SDK, PowerVR SDK, XML (DocumentBuilderFactory), SVN.
Technologies: Subversion (SVN), OpenGL, JBuilder, Eclipse, Xcode, Visual Studio, Objective-C, C++, C, BREW, J2ME

Web Developer

2003 - 2005
CTS Media GmbH
  • Designed and developed a CMS in PHP4 + mySQL employed in projects of the company; developed site-specific modules for this system and other CMS (eZ Publish, MAXcms).
  • Designed and programmed CMS-based sites (mainly e-shops).
  • Created the graphical design of sites and UI elements.
  • Designed and programmed Flash animations (intros, trailers) and components (menus, maps, etc.).
Technologies: HTML, JavaScript, MySQL, PHP

Web Developer

2001 - 2003
  • Created business sites and programmed separate components like menus and Flash banners.
  • Participated in the graphic design for some of the projects.
Technologies: Adobe Photoshop, Flash, ASP, JavaScript, HTML

SimpleTime API

I developed a PHP and SQL-based timesheet service implemented as a REST API. This back end is the foundation for the SimpleTime app, enabling users to track and manage their work hours effectively.

SimpleTime App

I created a simple timesheet web application using JavaScript and jQuery. This application seamlessly connects to a REST API on the back end, ensuring smooth communication and data exchange.

Author of an open-source library, written in JavaScript, for applying 3D transformations, animations, and scripting logic to HTML elements.

CFriendlyCell Image Recognition

I implemented a C++ class within an image recognition system that utilizes the SDL library. This class is critical in identifying objects within images by employing a multi-pass approach to merge neighboring areas, referred to as Friendly Cells, that exhibit similarity. This technique contributes to the system's accuracy and effectiveness in recognizing and delineating objects within the images it processes.


JavaScript, PHP, HTML, C, Objective-C, XML, XSLT, C++, SQL


jQuery, OpenGL, OpenGL ES, OpenCV, SDL, REST APIs


Debugging, HIPAA Electronic Data Interchange (EDI), SAP IDoc, Research & Critical Thinking




Visual Studio, TortoiseSVN, Git, Apache HTTP Server, Flash, Xcode, JBuilder, Subversion (SVN), Adobe Photoshop, 3ds Max


J2ME, BREW, Eclipse


MySQL, Oracle SQL

2002 - 2004

Master's Degree in Computer Science

Ruse University - Ruse

1998 - 2002

Bachelor's Degree in Computer Science

Ruse University - Ruse