We're actively hiring at Recommendations@Twitter: - Backend Engineers - Full Stack Engineers - Machine Learning/Relevance Engineers I lead the user, content and email recommendation team at Twitter. I have built the who-to-follow service, tie strength prediction engine, user similarity pipeline, user influence scoring, new user signup flow, email scheduling system, content optimization backend, etc. Before joining Twitter, I had fun building quantitative models in finance at Morgan Stanley. I earned my PhD in Computer Science from University of Illinois at Urbana-Champaign in 2011. I was advised by Professor Jiawei Han, and published 18 top conference and journal papers in data mining with 800+ citations during PhD study. I received my bachelor's degree in Computer Science from Fudan University in 2007 with highest honors (GPA 1st/160). I studied at Hong Kong University of Science and Technology as exchange student in 2005. I have interned at Google and Microsoft Research labs in three continents (Redmond, Cambridge, Beijing).