bio

Hongyuan Mei is currently a Member of Technical Staff at xAI. As a core contributor to Grok, he developed the methods that enabled Grok 4 Heavy, which achieved state-of-the-art on Humanity’s Last Exam.

Before joining xAI, I was a Senior Research Scientist at Google DeepMind. Before DeepMind, he was a Research Assistant Professor at Toyota Technological Institute at Chicago (TTIC), a research institute affiliated with University of Chicago. At TTIC, he led the River Lab, conducting research on AI reasoning and planning. Hongyuan Mei received PhD in Computer Science from Johns Hopkins University, advised by Jason Eisner. Hongyuan and Jason developed the neural Hawkes process, a model widely used in event sequence modeling and prediction.

Hongyuan’s research has been supported by a Bloomberg Data Science PhD Fellowship, the 2020 JHU Jelinek Memorial Award, and research gifts from Adobe and Ant Group. His technical innovations have been integrated into real-world products such as Alipay, the world’s largest mobile digital payment platform, which serves more than one billion users. His research has been covered by Fortune Magazine and Tech At Bloomberg.

Before joining JHU, Hongyuan obtained two MS degrees from University of Chicago, and did research in natural language processing with Mohit Bansal and Matthew R. Walter at TTIC. Prior to that, he obtained a BE in Electrical Engineering and a BA in Finance from Huazhong University of Science and Technology.