Weights & Biases builds a developer platform for tracking machine learning experiments, managing datasets and models, and deploying AI applications, widely used by machine learning teams to monitor training runs and compare model performance. The company was founded in 2017 by Lukas Biewald, Chris Van Pelt, and Shawn Lewis.
CoreWeave completed its acquisition of Weights & Biases in May 2025, a deal announced two months earlier at a $1.7 billion valuation. The acquisition pairs the GPU cloud infrastructure CoreWeave already provides to AI labs with the developer tooling layer that sits on top of it, a similar logic to Google's earlier acquisition of Wiz. Weights & Biases now operates as part of CoreWeave rather than as an independently funded company.