Steve Xie spent years leading simulation at Cruise and NVIDIA before founding Lightwheel — and in that time he watched simulation go from a tool that was "great for showcasing to investors" to what he believes will become the core infrastructure layer for all of physical AI. In this episode, we sit down with Steve to break down Lightwheel's three-pillar framework for simulation infrastructure: World, Behavior, and Evaluation — and why getting all three right is what separates serious simulation...