The Team Facebook Bought for $1 Billion
Role: Co-founder and lead software engineer
A fellow Stanford alum, Krieger has remained largely out of the spotlight—not unusual for a lead engineer. But his handiwork is all over Instagram's design and development. The co-founder interned at Microsoft and graduated from Stanford in 2009 with a BS in Symbolic Systems and an MS in Human Computer Interaction. After graduation, Krieger joined the Web messenger service Meebo as an engineer and user-experience designer.