Enterprise search allows users in an enterprise to retrieve desired information through a simple search interface. It is widely viewed as an important productivity tool within an enterprise. While Internet search engines have been highly successful, enterprise search remains notoriously challenging due to a variety of unique challenges, and is being made more so by the increasing heterogeneity and volume of enterprise data. On the other hand, enterprise search also presents opportunities to succeed in ways beyond current Internet search capabilities. This tutorial presents an organized overview of these challenges and opportunities, and reviews the state-of-the-art techniques for building a reliable and high quality enterprise search engine, in the context of the rise of big data. © 2014 VLDB Endowment 2150-8097/14/08.