Search is one of the most important applications used on the Internet and poses interesting challenges in computer science. Providing high-quality search requires understanding across a wide range of computer science disciplines. In this program, Google Fellow Jeff Dean describes some of these challenges, discusses applications Google has developed, and highlights systems they’ve built, including GFS, a large-scale distributed file system, and MapReduce, a library for automatic parallelization and distribution of large-scale computation. He also shares observations derived from Google's Web data. From the Series:CSE Colloquia - 2005