Weights & Biases

Weights & Biases (W&B) is an AI developer platform founded in 2017 in San Francisco and acquired by CoreWeave in 2025. It helps machine learning teams track experiments, run hyperparameter sweeps, version datasets and models, and evaluate LLM and agent applications through its Weave toolkit. Since September 2026, W&B is offered as part of CoreWeave Forge, a development environment that also includes model registry, serverless inference, post-training, notebooks and sandboxes; existing W&B cloud users access their projects through Forge. W&B can be used as SaaS or in dedicated and customer-managed deployments.

• Experiment tracking for metrics, hyperparameters and artifacts
• Sweeps for automated hyperparameter search
• Weave for tracing and evaluating LLM and agent applications
• Registry for versioned models and datasets
• Available within CoreWeave Forge alongside inference, notebooks and sandboxes