During his childhood Harry seemed to be doing everything right -- learning to program BASIC on Thomson TO-7s (whose rubber keys went "boop" when you pressed them) and Logo on a Green-screen Amstrad PCW. Something went wrong as he grew up, and Harry wasted several years studying Economics, becoming a management consultant (shudder), and programming little aside from overcomplicated Excel spreadsheets.
But in 2009 Harry saw the light, let his true geek shine once again, did a new degree in Computer Science, and was lucky enough to secure an internship with Resolver Systems, the London-based company that has since morphed into PythonAnywhere. Here he was inculcated into the cult of Extreme Programming (XP), and rigorous TDD. After much moaning and dragging of feet, he finally came to see the wisdom of the approach, and now spreads the gospel of TDD through beginner's workshops, tutorials and talks, with all the passion of a recent convert.
Harry is the author of an O'Reilly book called "Test-Driven Development with Python", but he's hoping everyone will just call it "The Goat Book".