Weights & Biases

Weights & Biases is a US AI developer platform company, founded in 2017 in San Francisco by Lukas Biewald, Chris Van Pelt and Shawn Lewis, and acquired by CoreWeave in 2025 while continuing to operate under its own brand. The company was built to help machine learning teams track experiments and move AI projects from research into reliable production systems.

The platform combines experiment tracking, hyperparameter optimization and dataset visualization with a GenAI toolkit called Weave for building and evaluating agentic applications, plus a model registry and flexible SaaS, dedicated or customer-managed deployment options. Enterprise customers include Meta, Microsoft, NVIDIA, Toyota and Salesforce.

1. Experiment Tracking: Logs metrics, hyperparameters and artifacts for every model training run.

2. Sweeps: Automates hyperparameter search to find the best-performing model configurations.

3. Weave: Provides tracing, evaluation and a playground for building and debugging AI agents.

4. Model Registry: Centralizes versioned models, datasets and prompts for team-wide reuse.

5. Inference: Serves hosted AI models for production applications.

6. Flexible Deployment: Supports SaaS, dedicated and customer-managed hosting for enterprise security needs.