What is the job of a facebook developer?

[Sephora]

[David N]

Developing either Facebook itself, or applications that run on Facebook.

[another911]

From time to time he rearranges the book's face

[ItachisXeyes]

building the site and its interface.
there are other groups that actually manage them, and attempt to secure them.

[Marc C]

No doubt everything from layout, design, and visual features to writing the FB network itself. Alpha/Beta testing for new releases - Lots of bug testing. Same idea as the job of a normal software developer.

[Jai]

The same work what web application developers do, is the same thing that the FB developers also do........ Design to developing software..........