Patrick Pijnappel, Software Developer in Melbourne, Victoria, Australia
Patrick Pijnappel

Software Developer in Melbourne, Victoria, Australia

Member since February 10, 2016
Patrick has been deeply passionate about programming since the age of 12. He is a longtime freelancer, co-founder of Archimedes, and a contributor to experimental AI research and the Swift language itself. He thrives on the really hard problems, clean architecture and advanced performance optimization. He has coded in over a dozen different languages and can pick up new languages and technologies very quickly.
Patrick is now available for hire




Melbourne, Victoria, Australia



Preferred Environment

Git, Xcode, MacOS

The most amazing...

...thing I've developed is a next-generation graphing calculator with custom mathematical typesetting and custom symbolic solving engine.


  • Co-founder

    2011 - 2018
    Archimedes Calculator
    • Designed and developed Archimedes, a next-generation graphing calculator for iOS.
    • Created a unique, fully-interactive mathematical typesetting system with fluid animation.
    • Wrote a custom symbolic math solving engine with automatic unit handling.
    • Implemented high-quality plotting functionality including smooth touch-based scroll/zoom, automatic POI detection, and direct-interaction tracing, differentiation, and integration tools.
    • Began developing an advanced experimental new type of symbolic math engine.
    Technologies: iOS, Objective-C, Swift
  • Co-founder

    2016 - 2017
    • Developed a location-based video sharing platform.
    • Figured out a way to have a performant feed of up to 16 simultaneously playing streaming video tiles.
    • Wrote frameworks for declarative endpoint specification, futures/promises, model parsing, model persistence, and change notification.
    Technologies: AVFoundation, Node.js, Swift
  • Arduino/iOS Developer

    2011 - 2017
    DKP Veterinary Clinic
    • Created the software for a wifi-enabled advanced experimental operating table with Arduino-controlled electronics and an iPad interface.
    • Created the software for an experimental network of veterinary animal cells with lighting, heating, ventilation, and oxygen supply systems controlled by a distributed set of Arduinos communicating with an iPad interface.
    • Wrote a robust communication layer between a network of Arduinos and iOS devices using a simultaneous mixture of serial, I2C, and wifi channels.
    • Interfaced with a large number of different analog and digital sensors and actuators over a variety of different protocols.
    • Created a messaging system for generically binding sensors and settings on Arduinos to properties on iOS devices, automatically managing communication over a mixed channel network.
    Technologies: iOS, Swift, Objective-C, Arduino, C++
  • iOS Developer

    2015 - 2016
    • Created an iOS front-end app for a dynamic CRM application.
    • Wrote encapsulation for communication with a legacy REST back-end with consistent error handling.
    • Created dynamic UI for display and manipulation of records with arbitrary fields of different data types.
    • Created a self-contained encapsulation of a complex workaround for broken call tracking API.
    • Created dynamically fetching browse and search functionality for working with large record sets.
    Technologies: iOS, Swift
  • Java Developer

    2011 - 2011
    • Developed the third version of a leading forensics application for the measurement of suspects by joining camera images with point cloud data from 3D laser scans of the crime scene.
    • Completely transformed a large, undocumented old codebase into a clean, stable, and organized one.
    • Wrote code for 3D navigation, rendering, and manipulation using OpenGL.
    • Wrote code to load, manipulate, and render large datasets in a performant way.
    • Redesigned, localized, and generally modernized the UI.
    Technologies: OpenGL, C, Java


  • Swift Standard Library

    l've been one of the top non-Apple contributors to the Swift language and standard library since it became open-source. I primarily do performance optimization, rewrites, and spotting of edge cases in the standard library. Some of the more interesting ones include and

  • Archimedes

    A next-generation scientific calculator with custom smoothly animated mathematical typesetting, lots of custom UI, and a custom symbolic math engine underneath.

  • Machino

    Graduation project on an OS X application for the design of Arduino programs using finite state machines, including live runtime visualization of the executing Arduino code (Objective-C).


  • Languages

    Objective-C, Swift, Java, C, C#, Python, JavaScript, CSS, HTML, C++
  • Frameworks

    Cocoa Touch, Windows Presentation Foundation (WPF), Cocoa, .NET, Express.js
  • Tools

    Xcode, Git, Adobe Photoshop, Adobe Illustrator
  • Platforms

    iOS, Arduino, MacOS
  • Other

    Computer Graphics, AVFoundation
  • Libraries/APIs

    OpenGL, GMP, Node.js, XNA
  • Storage



  • Master's (with Honors) Degree in Design for Interaction
    2011 - 2013
    Delft University of Technology - Delft, The Netherlands
  • Bachelor's Degree in Aerospace Engineering
    2007 - 2010
    Delft University of Technology - Delft, The Netherlands

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