Facebook has long been a leading force in the development of big data. The recent release of Graph Search is seen as a move by the company to flex their big data muscles and put their engineering bona fides to the test.
A couple of good articles came out this week discussing the engineering challenges Facebook is taking on with this project. Zach Miners, at IT World, explains the work the new tool does searching large graphs with this article. Harpreet, at Tools Journal, wrote a good piece explaining how Natural Language Processing is used by Graph Search.
One last article I would like to highlight is a glossary of big data at Facebook that was put out by Wade Roush at Xconomy.
A Data Head's Diary 