Weights & Biases (W&B)

W&B is the "Github for ML models". It tracks every run, hyperparameter, and artifact. 2025 brings W&B Inference and Weave.

When to Use

• Visualization: Live loss curves during training.
• Collaboration: Sharing reports ("The loss spiked here") with teammates.
• Model Registry: Managing lifecycle.

Core Concepts

W&B Run

A single experiment.

Sweeps

Hyperparameter optimization engine.