1 PHP at Yahoo! http://public.yahoo.com/~radwin/ Michael J. Radwin October 20, 2005 2 Outline • Yahoo!, as seen by an engineer • Choosing PHP in 2002 • PHP architecture at Yahoo! 3 The Internet’s most trafficked site 4 25 countries, 13 languages 5 Yahoo! by the Numbers • 411M unique visitors per month • 191M active registered users • 11.4M fee-paying customers • 3.4B average daily pageviews Octob