Taner Halicioglu was Facebook's first "real" employee outside of the founders. He built out the entire initial hardware infrastructure.

Employed by Facebook from: October 2004 - November 2009

Position at Facebook: Senior Software/Operations Engineer

Where he is now: Halicioglu became the Lead Reliability Engineer of Battle.net at Blizzard Entertainment. Now he is a lecturer at UC San Diego in the school's Computer Science and Engineering department.