Jeff joined Google in 1999 and is a Senior Fellow in Google's Research Group, where he currently leads the Google Brain team, Google’s deep learning research team. He has co-designed/implemented five generations of Google's crawling, indexing and query serving systems, and major pieces of Google's initial advertising and AdSense for Content systems. He is also a co-designer and co-implementor of Google's distributed computing infrastructure, including MapReduce, BigTable, Spanner and TensorFlow. He is currently working on large-scale distributed systems for machine learning, and on the use of these systems in speech recognition, computer vision, language understanding, and various other domains. He is a member of the U.S. National Academy of Engineering, and a Fellow of the ACM and the AAAS.