Hongyuan Mei

I train computers to reason about the world.

Currently, I am training Grok to be a knowledgeable reasoner. As a core contributor to Grok, I developed the methods that enabled Grok 4 Heavy, which achieved state-of-the-art performance on Humanity’s Last Exam.

Before joining xAI, I was a Senior Research Scientist at Google DeepMind.

Before DeepMind, I was a Research Assistant Professor at Toyota Technological Institute at Chicago (TTIC), a research institute affiliated with University of Chicago. At TTIC, I led the River Lab, conducting research on AI reasoning and planning.

I received PhD in Computer Science from Johns Hopkins University, advised by Jason Eisner. We developed the neural Hawkes process, a model widely used in event sequence modeling and prediction.