Pawel Leszkiewicz, iOS Developer in Warsaw, Poland
Pawel Leszkiewicz

iOS Developer in Warsaw, Poland

Member since May 6, 2019
When Pawel was eight, he saw a computer game for the first time and from then on he knew he would become a software engineer. With more than 15 years of experience under his belt, Pawel’s primary interests are in app development and computer graphics—specializing in mobile tech (iOS, React Native) and everything related to 3D graphics (AR/VR/MR). Pawel has worked for Codemasters, CD Projekt RED, Chaotic Moon, and Magic Leap.
Pawel is now available for hire


  • Nomtek
    Core Video, Core Graphics, Realm, SQLite, Core Data, OpenGL, REST...
  • CD Projekt RED
    Microsoft Foundation Class Library (MFC), Windows API, C, C++
  • Codemasters
    Graphics Processing Unit (GPU), HLSL, C++, .NET, C#



Warsaw, Poland



Preferred Environment

Sketch, Git, Visual Studio Code, Xcode, MacOS, iOS

The most amazing...

...project I've ever worked on was a mixed reality game. A user could use a digital paddle to hit a virtual ball that bounces off real objects.


  • Software Engineer

    2010 - PRESENT
    • Delivered and maintained over 50 iOS applications from various areas (health, education, eCommerce, sport, games, business, tools, and more).
    • Implemented a 3D page curl effect when it wasn't yet supported natively (Objective-C).
    • Worked in various-sized teams of 1 to 30 people (locally and worldwide) in several roles from a regular programmer through a senior tutor to a team leader.
    • Conducted thoughtful code reviews.
    • Worked remotely, often visiting clients in their office or inviting them to the company's office in Poland.
    • Participated in both the recruitment process of new employees and the process of searching and acquiring new customers.
    • Represented the company at trade shows and conferences (Apps World, CES, MCE, and LEAP Conference).
    • Cooperated with clients at all possible stages (sales, consulting, PoC, prototype, development, maintenance, SLA).
    • Worked directly for companies like Magic Leap, Chaotic Moon, Marley Spoon, TUI, PONS, Collectomate, Creatubbles, and Eleiko.
    Technologies: Core Video, Core Graphics, Realm, SQLite, Core Data, OpenGL, REST, Bluetooth LE, Windows, Mixed Reality (MR), Virtual Reality (VR), Augmented Reality (AR), React Native, Objective-C, Swift, iOS
  • Experienced Tools Programmer

    2009 - 2010
    CD Projekt RED
    • Supported and developed the Witcher game editor.
    • Created a thread-safe logger that outputs debug text to the console (C++).
    • Contributed to the builds of a custom IDE for editing Lua scripts.
    • Implemented a game console panel that allowed users to make various queries.
    Technologies: Microsoft Foundation Class Library (MFC), Windows API, C, C++
  • Experienced Tools Programmer

    2007 - 2009
    • Worked on the game Operation Flashpoint: Dragon Rising.
    • Participated in the development of the mission editor tool that was released together with the main game. (C#, .NET).
    • Designed and developed several internal tools at different platforms (Windows, PS3, Xbox 360).
    • Maintained a continuous integration and deployment process for the AAA game.
    • Created and supported a particle editor together with a reusable view component that allowed rendering of the 3D scene in both the cross-platform game engine and in the internal tools.
    Technologies: Graphics Processing Unit (GPU), HLSL, C++, .NET, C#
  • Graduate Design Engineer

    2007 - 2007
    Imagination Technologies
    • Developed simulators for video IP cores.
    • Refactored a project written in a structural language into an object-oriented language (C++).
    Technologies: Standard Template Library (STL), C, C++
  • Software Developer

    2004 - 2007
    • Designed and developed a particles editor used for creating multiple visual effects.
    • Created a set of 3D brushes that helped designers to model a 3D terrain.
    • Implemented an audio editor for creating and tweaking sounds effects.
    • Designed and implemented a set of UI elements used by the game engine.
    • Made a swarm motion algorithm to simulate bird movement.
    Technologies: PhysX, Game Engine Programming, Rendering, Graphics Processing Unit (GPU), OpenGL, Sound, DirectX, .NET, C#, C++


  • B-all One

    B-all One is the first publicly available game on Magic Leap One that was entirely developed in Lumin SDK (C++).

    The game lets you play with a virtual racquet and ball in your room. The digital ball bounces off the real obstacles giving the impression of playing with a real ball.

    The project was demanding due to the early version of the software and hardware components which did not always work as expected.

  • Collectomate

    Collectomate is a platform that provides software and hardware solutions that makes it easier for couriers to deliver and for recipients to pick up parcels.

    My responsibility was to create a cross-platform (React Native, iOS, Android) mobile application which notifies the recipients about the delivery of the package and helps them to locate the package, indicating the appropriate locker. Additionally, there was a second application which was installed on the tablet embedded in the Collectomate unit.

    The tablet app is used by couriers and office staff to deliver the packages and maintain the unit.

  • 360° Video Player

    This is an open source 360° video player made for iOS (Swift, OpenGL). Each frame of the 360° video is mapped onto a sphere giving the impression that the viewer is in the middle of the action.

  • Creatubbles

    Creatubbles is a social platform for children, teachers, and parents. The service allows children to share their work (creations) with other children around the world.

    My role was to develop and maintain the code of iOS app (Obj-C and Swift), conduct code reviews, and write unit tests and UI tests.

    It was a challenging project in terms of effective communication because almost every team member came from a different country.

  • Employee Management Application

    I contributed to a big project that was designed for the web, iOS, and Android. When I joined the team, I came across a legacy code that was unstable and inefficient. The nickname of the project was "Broken Window" because it was too advanced to start over, but it was also in too bad of condition for on-time delivery.

    Together with the team, we developed a strategy that enabled us to deliver a stable product with only a slight delay. In this project, I learned a lot about the importance of being transparent, effective communication and efficient cooperation of the whole team.

  • Marley Spoon

    Marley Spoon allows users to order ingredients and recipes making it easy to cook meals at home.

    I was the delivery leader of a two-person team that was to deliver the MVP version to the customer. Because the client was perfectly prepared and came to us with all the well-thought-out requirements, we managed to complete the MVP on time and without any unexpected problems (iOS, Objective-C).

  • File Manager

    I was responsible for developing and maintaining an iOS application that is used to download, organize, and view files on iPhone and iPad. The application integrates external storage services such as Dropbox, Google Drive,, OneDrive. It supports opening large images, listening to sound files, previewing presentations, remote document printing, and more.

  • FlipCards

    FlipCards is an iOS application designed to enhance the process of memory training and learning foreign languages. It is a visualization of the popular flashcard learning system.

    This was my very first iOS project that was released to the App Store. It was featured by Apple for its graphics and educational style. The app was also mentioned in the Washington Post in 2012.

  • Wall Map

    As a private personal project, I designed and implemented a wallpaper with a map of the world that covers a wall with the measurements of 3m x 2.6m.

    The map was made from 16,000 small tiles of images fetched from Google Maps API (macOS, Objective-C). The tiles were merged into three big images (+2 GB) and were printed off on the HP DesignJet L26500. The map is currently hanging on a wall in my room.

  • Miscellaneous Projects (2001-2206)

    In the course of my career, I developed a number of applications and games in high school and college (2001-2006).

    • World Engine (C++, OpenGL): a game engine that shows my use of algorithms for space partitioning (Octree, BSP Tree, portals)
    • Fluid Motion (C++, DirectX, HLSL): a simulation of water droplets flowing down on different surfaces; all of the computations were made on GPU
    • Number plate recognition app (C#, WinForms)
    • Graphs and fractals (Turbo Pascal): an application that won the national IT competition in the DOS category
    • Multiple games in OpenGL: 3D Billiards, Moonlander, Battle Tanks, and more
    • Reversi (Java): a popular board game
    • Wolf (C): a clone of the popular game Wolfenstein


  • Languages

    Swift, Objective-C, C, C++, C#.NET, Google Apps Script, C#, Cg, HLSL, Java, HTML, JavaScript
  • Frameworks

    Cocoa Touch, ARKit, iOS SceneKit, UIKit, React Native, Core Data, .NET, PhysX, Core Video, Electron
  • Libraries/APIs

    OpenGL, Core Animation, Core Graphics, DirectX, OpenGL ES, Facebook iOS SDK, MapKit API, WinAPI, Microsoft Foundation Class Library (MFC), Windows API, Standard Template Library (STL)
  • Tools

    Lumin SDK, Xcode, Sketch, GitHub, GitLab, Adobe Photoshop, SourceTree, Jira, Trello, Git
  • Paradigms

    Mobile Development, Agile Software Development, Clean Architecture, VIPER Architecture, REST
  • Platforms

    iOS, Visual Studio Code, Firebase, MacOS, Windows Phone, Windows, Bluetooth LE
  • Storage

    JSON, SQLite, Realm
  • Other

    3D Graphics, Virtual Reality (VR), Mixed Reality (MR), Augmented Reality (AR), Image Processing, Graphics Processing Unit (GPU), 3D Games, 2D Games, In-app Purchases, Sound, Rendering, Game Engine Programming, UI Testing


  • Master's Degree in Computer Science
    2005 - 2006
    Warsaw University of Technology - Warsaw, Poland
  • Bachelor's Degree in Computer Science
    2001 - 2005
    Warsaw University of Technology - Warsaw, Poland

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