Rerun is the data layer for Physical AI; robotics, autonomous systems, AR/VR, and other embodied ML. We give engineers a single unified layer for multi-rate, multimodal data: the open-source Rerun SDK (Rust, built with egui) for logging, querying, visualizing, and training, plus Rerun Hub for large-scale storage and streaming from object storage. Most of our core, performance-critical code is Rust.