Dan Chak's varied education in real-world web architecture gives him a unique perspective on the challenges of building rock-solid web applications. Dan has worked at Amazon.com, the world's biggest online retail store, where seemingly small technology problems become big ones due to enormous scale. Dan also directed software development at CourseAdvisor Inc., a Ruby on Rails startup company. A nearly instant success, CourseAdvisor was acquired by the Washington Post Company in October 2007. You can hear his thoughts on his blog at http://blog.chak.org.