Cathy Qian is currently a Senior Machine Learning Engineer at Pinterest, with expertise in developing large scale end-to-end machine learning solutions. She has previously worked at Twitter and Expedia, where she helped build and deploy machine learning applications in ads and search ranking systems. She has received a Ph.D. degree from the University of Pennsylvania and published 20+ research papers in high-impact peer-reviewed journals before transitioning to the high-tech industry. She enjoys writing and knowledge sharing in her spare time.