Ted Dunning is Chief Applications Architect at MapR Technologiesand active in the open source community, being committer and PMC member of the Apache Mahout, Apache ZooKeeper, and Apache Drill projects and serves as a mentor for these Apache projects: Storm, Flink, Optiq, Datafu and Drill. He has contributed to Mahout clustering, classification, matrix decomposition algorithms and new Mahout Math library, and recently designed the t-digest algorithm used in several open source projects. He also architected the modifications for Open TSDB described in this book. Ted was the chief architect behind the MusicMatch (now Yahoo Music)and Veoh recommendation systems, built fraud-detection systems forID Analytics (LifeLock), and has issued 24 patents to date. Ted has aPhD in computing science from University of Sheffield. When he's notdoing data science, he plays guitar and mandolin. Ted is on Twitter at@ted_dunning. Ellen Friedman is a solutions consultant and well known speaker and author, currently writing mainly about big data topics.

She is a committer for the Apache Mahout project and a contributor to the Apache Drill project. With a PhD in Biochemistry, she has years of experience as a research scientist and has written about a variety of technical topics including molecular biology, nontraditional inheritance, and oceanography. Ellen is also co-author of a book of magic-themed cartoons, A Rabbit Under the Hat. Ellen is on Twitter at @Ellen_Friedman.