I gave this presentation at the RecSysChallenge workshop (http://2012.recsyschallenge.com/) at Recommender Systems 2012 (http://recsys.acm.org/2012/) in Dublin on 13 September, 2012. This presentation describes how we have been making use of Mahout to power Mendeley Suggest. First, it includes some results from tuning Mahout's recommender on AWS and the cost vs. precision tradeoff. Then it concludes with details on how to make use of other big data technologies and AWS in order to put a serving layer in place. Acknowledgement to Daniel Jones for making the slides for the serving layer part of the presentation.