Alexandros is a Senior Research Scientist at Telefonica Research working on Machine Learning. Alexandros received his PhD in Machine Learning from the Vienna University of Technology (TUWIEN). During his PhD he was a frequent visitor to the Statistical Machine Learning group at the ANU/NICTA in Canberra Australia. He has over 40 papers in the field and has won 3 best paper awards at the ACM RecSys and ECMLPKDD conferences. He has developed several ranking techniques for collaborative filtering, context-aware recommendation methods and techniques for recommendations in a social network. He is also the author of the core machine learning R package kernlab, and enjoys giving lectures on Machine Learning, Recommender Systems and R.