Weights & Biases

Acquired by CoreWeave in 2025, Weights & Biases‘ mission is to build the best tools for artificial intelligence developers.

Build better models faster, fine-tune large language models (LLMs), develop generative AI applications with confidence, all in one system of record. Weights & Biases Models is the machine learning operations solution used by foundation model-builders and enterprises that are training, fine-tuning and deploying models into production. W&B Weave is the LLM operations solution for software developers who want a lightweight but powerful toolset to help them track and evaluate LLM applications. Weights & Biases is trusted by more than 1,000 companies to productionise AI at scale, including teams at OpenAI, Meta, NVIDIA, Cohere, Toyota, Square, Salesforce and Microsoft.