Stoyan Stefanov is a Facebook engineer, author, and speaker.He talks regularly about web development topics at conferences and his blog www.phpied.com, and also runs a number of other sites, including JSPatterns.com-a site dedicated to exploring JavaScript patterns. Previously at Yahoo!, Stoyan was the architect of YSlow 2.0 and creator of the image optimization tool Smush.it. A "citizen of the world," Stoyan was born and raised in Bulgaria, but is also a Canadian citizen, currently residing in Los Angeles, California.In his offline moments, he enjoys playing the guitar, taking flying lessons, and spending time at the Santa Monica beaches with his family.