David Chappell is Principal of Chappell & Associates in San Francisco, California. He has been the keynote speaker for events on five continents, and his seminars have been attended by tens of thousands of developers, architects, and decision makers in forty countries. David’s books have been published in a dozen languages, and used regularly in courses at MIT, ETH Zurich, and other universities. His consulting clients have included Microsoft, IBM, Target, Stanford University, and others.