Janusz Gregorczyk

Janusz Gregorczyk

Szczecin, Poland
Hire Janusz
Scroll To View More
Hire the top 3% of freelance developers
toptal.com
Call us: +1.888.604.3188
Janusz Gregorczyk

Janusz Gregorczyk

Szczecin, Poland
Member since July 6, 2014
Janusz is an experienced iOS developer who has developed more than 40 iOS apps from scratch over the last few years while working on many more. Before that, he was a co-founder of Gameleons (in its prime time, one of Poland's biggest mobile development teams) and worked on over 50 mobile Java games.
Janusz is now available for hire
Hire Janusz
Portfolio
  • Doist
    iOS, Swift
  • codesize
    Objective-C, iOS SDK, Git, UIKit, Instruments, OpenGL, Cocos2d
  • Bright Mediums
    Objective-C, iOS SDK, CoreData, Multithreading, Parse.com
Experience
  • C, 10 years
  • C++, 10 years
  • Objective-C, 5 years
  • Core Data, 5 years
  • iOS, 5 years
  • AFNetworking, 3 years
Szczecin, Poland
Availability
Part-time
Preferred Environment
Xcode, Git
The most amazing...
...thing I've coded was a Doom-style game engine in mobile Java.
Employment
  • iOS Developer
    Doist
    2014 - PRESENT
    • Developing iOS apps in Swift.
    Technologies: iOS, Swift
  • Independent software developer (self-employed)
    codesize
    2008 - PRESENT
    • Worked remotely with businesses worldwide.
    • Specialized in mobile application development, particularly the iOS platform.
    • Developed about 40 iOS applications from scratch and worked on many more.
    Technologies: Objective-C, iOS SDK, Git, UIKit, Instruments, OpenGL, Cocos2d
  • Senior iOS Engineer
    Bright Mediums
    2013 - 2014
    • Developed and maintained of several challenging iOS projects.
    • Worked in an Agile team.
    • Provided expertise in multithreaded CoreData, CoreLocation, UIKit.
    Technologies: Objective-C, iOS SDK, CoreData, Multithreading, Parse.com
  • Senior iOS Developer
    AppwoRx LLC
    2013 - 2014
    • Worked on a 2.0 version and subsequent enhancements of a clinical photography application.
    • Almost completely rewrote the iOS code base, developing an iOS universal application, heavily interfacing with a REST-ful back end.
    Technologies: Objective-C, iOS SDK, CocoaPods, Interface Builder, Universal App, REST
  • Mobile Hero
    Brothers Media
    2010 - 2013
    • Developed several beautifully designed iOS universal applications featuring in-app purchases, maps, and push notifications.
    Technologies: Objective-C, UIKit, CoreAnimation, CoreLocation, MapKit, In-App Purchases
  • CTO, Co-founder
    Gameleons Sp. z o.o.
    2005 - 2008
    • Managed development and R&D activities of one of Poland's top mobile game studios of the time.
    • Involved in over 40 J2ME projects, from conception to post-production maintenance.
    • Developed several game engines, a local Bluetooth multiplayer solution, and a core porting technology.
    Technologies: J2ME, Java, Python, continuous integration
  • C/C++ Programmer / Contractor
    InterActive Vision Mind Beacon Sp. z o.o.
    2003 - 2004
    • Helped port two arcade simulator games from PC to the PlayStation 2 platform: Operation Air Assault and Pacific Warriors 2.
    • Worked on platform and compiler porting of large Visual C++ code base to PS2 and GCC.
    • Implemented PS2-specific features.
    • Performed subsequent optimization and bug fixing.
    Technologies: C, C++, Visual C++, GCC, PlayStation, RenderWare, Subversion
  • C/C++ Programmer
    InterActive Vision Mind Beacon Sp. z o.o.
    2001 - 2003
    • Programmed a variety of applications on Palm OS and Windows Mobile.
    • Developed game back end, parts of user interface and various other components of the PC game Airlines 2.
    Technologies: C, C++, Visual C++, WinAPI, Palm OS, Pocket PC, Subversion
Experience
  • Zonnesimulator for Eneco (Development)

    Solar panel planner / calculator for an international sustainable energy company.

    I worked on UIDocument-based renewable energy calculator and used complex CoreAnimation transforms.

  • RxPhoto for AppWorks LLC (Development)
    http://myappworx.com/rxphoto/

    I was responsible for the 2.0 release of this clinical photography application. It was an almost-total rewrite of the iOS codebase, developing an iOS universal application heavily interfacing with a REST-ful backend.

  • Ahold Experience for Ahold Europe (Development)

    Corporate training/gamification app.

    Used Vuforia SDK, OpenGL, and AVFoundation for AR video display.

  • The Bovenkant van Nederland for Scriptum Publishers (Development)

    Aerial photography album.

    Developed a custom interface with lots of CoreAnimation, MapKit, IAPs, CoreLocation.

  • Dinosaurs for Kids for Potrus Publishing Sp. z o.o. (Development)
    https://itunes.apple.com/pl/app/dinosaurs-for-kids.-untold/id498477611?mt=8

    Interactive book based on custom OpenGLES/C++ engine with Lua and Box2D.

Skills
  • Languages
    C, Objective-C, C++, Swift, Python, Java, JavaScript, C#
  • Frameworks
    Cocoa, ZURB Foundation, Core Data, Cocos2d, AV Foundation
  • Platforms
    iOS, Android
  • Misc
    UI Kit
  • Libraries/APIs
    AFNetworking, CocoaPods, Parse iOS SDK, Core Animation
  • Tools
    Git, GitHub, TextWrangler, Bitbucket, Xcode
Education
  • MSc degree in Electronics Engineering
    Zachodniopomorski Uniwersytet Technologiczny w Szczecinie - Szczecin, Poland
    1999 - 2004
Hire the top 3% of freelance developers
toptal.com
Call us: +1.888.604.3188
To view more profiles, join ToptalJoin Toptal
I really like this profile
Share it with others