Not-technical "The World's Toughest Endurance Challenges" - Very nicely illustrated "Thing Explainer: Complicated Stuff in Simple Words" - Extremely enjoyable. People here certainly are aware of xkcd and it's type of humor. Technical "Functional programming in Scala" - good read for Scala beginners, especially after "Scala for the Impatient" "Learning Spark" - the best book on Spark so far "Assessing and Improving Prediction and Classification" - couple of interesting ideas for ML and Data Science "Neural Network Design" - Quite basic, but I like the flow and introducing mathematical concepts just before they're needed.
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