Green Pixel Software

Mobile Software Engineering - iOS & Android


Green Pixel Software is me, Christopher O'Brien, a mobile engineer with a passion for the product.

I’ve worked as an iOS Developer since 2011 across multiple industries such as sports betting, event management and broadcasting. I believe strongly in the engineering team working closely with the product team to build stable and scalable applications with great UI and UX. The devil is truly in the details and focusing on them is what produces an amazing application.

I see myself as a well-rounded mobile engineer, having also worked across a variety of Android projects since 2011. In the past year I have focused on expanding my skill set to become more of a Full-Stack engineer, working on server-side projects in Spring (Java and Groovy), along with web front-end projects using Angular 2.

I believe that having a clearly defined but open-minded approach to software engineering helps to produce best results.


Consistent, scalable structure and behaviour with clear and well-defined layers.


Expressive services, components and classes that are highly cohesive, loosely coupled, with clearly defined interfaces.


Power applications using Test Driven Development (TDD) and a suite of UI tests.

Core Skills

It's important to know where one can improve

Angular 2



  • Work experience

  • E L E V E N, London UK - Senior Mobile Developer

    Building original products for the gaming industry.
    Apps: Egon Zehnder, Goalrilla
    Mobile: iOS, Android
    Server: Spring, both Java and Groovy
    Web: Angular 2, Javascript, HTML, CSS

  • Sketch, London UK - Senior Mobile Developer

    Sketch is a London based venture studio bringing to market some of the most disruptive and innovative consumer-facing apps.
    Apps: Gousto, Patch, Echo, Just Eat
    Mobile: iOS, Android
    Server: Spring, both Java and Groovy
    Web: Javascript, HTML, CSS

  • British Sky Broadcasting, London UK - iOS Developer

    Sky Store is a streaming and download service allowing rentals and purchases of movies and TV shows.
    Apps: Sky Store
    Mobile: iOS

  • Betfair, London UK - iOS Developer

    Betfair is a betting exchange that handles more transactions than all of Europe’s stock exchanges combined.
    Apps: Betfair Exchange
    Mobile: iOS
    Agile: Scrum Master

  • Freelance, Cork IE - Mobile Developer

    Developed Kuro Mobile, an event management platform, which was a finalist in the University College Cork Entrepreneur of the Year competition
    Apps: Kuro Mobile
    Mobile: iOS and Android
    Server: PHP
    Web: Javascript, HTML, CSS

  • AgencyPort Software, Boston USA - Mobile Developer

    Project managed and developed the majority of a project with minimal supervision. The mobile application served the AgencyPort Annual Conference.
    Apps: APAC2012
    Mobile: iOS and Android

  • Credit Suisse, London UK - Intern Java Developer

    Development of a Java based API to monitor server health and performance.
    Server: Java
    Web: Google Web Toolkit

  • Other Employment

    Web Development Tutor. September 2012 – May 2013
    Nokia Mobile Phone Technician, IT Technician and Consultant. October 2006 – September 2009


“I couldn't recommend Chris enough - he's absolutely the kind of guy you want on your team. He's passionate about iOS development, always keeps up-to-date with the latest technologies and is continuously looking for better ways to produce award-wining software. He has an excellent grip on Agile methodologies (he served as scrum master on the Betfair iOS team for several months), coached other members on the team on TDD & interviewed possible candidates for roles on the iOS team. Time and time again, he drove the team to do 'the right thing' instead of 'the quick hack' and this proved to be invaluable when it came to maintaining a healthy codebase. I'd look forward to working with Chris again in the future.”

— Sean O'Shea | Principal Software Engineer

“Christopher got a long deserved promotion whilst I was working along side him for 3 months back in 2014. It was clear he progressed incredibly quickly and has gone on to really shine in developing some awesome apps. He's now at the top of his game (and definitely not one to stop improving). I would never hesitate working with him again.”

— James Hartt | Senior iOS Engineer


Feel free to contact me any time by email or phone for contract work or consultancy.