From assembly language though scripting languages, Java(Script) and SQL to Objective-C(++) and Swift, John has the answer to your low level engineering and performance and tuning requirements. Available for remote work in the Europe or US timezone John has been an independent iOS and MacOS dev since 2008.

This has focused on improving developer productivity, the first tool being injectionforxcode, a project that allows hot-loading code changes into a running application. For a while a third party Xcode plugin along with GitDiff, Refactorator, Remote and Xprobe now combined into a single dev tool. After building a Swift-Java bridge and porting Foundation to Android, John has also proposed and contributed the implementation of multi-line and raw string literals into Swift.

John's iOS app "iRail" was the first railway timetable application in the App Store. Subsequent work focused on an modular application that downloaded enterprise signed components of itself over the internet. A more recent contract has been to reverse engineer precisely how emails are rendered by Mail.app, Gmail and Inbox. Before this, John contracted in the Financial Services sector in Java, SQL and Perl.