I am a French consultant, based in Paris. I discovered Extreme Programming in 1998, when exploring the c2.com and other pattern-related sites. In 2000, I published the www.design-up.com website to promote XP here in France. In 2001, I co-authored the first XP book written in French (“Gestion de projet Extreme Programming”, Eyrolles). I have been working exclusively in XP since early 2001 - I have been involved in about 150 XP iterations. The largest project I have coached lasted for 4 years, and involved 25 developers, 500 KLOC of Java code and 20.000 tests. It was considered a major success. My focus now is on the technical aspects of agile development. How can one effectively fight software rot to prevent the software itself from dragging the project down? How should one train the team so that it becomes able to grow the design efficiently over the years?