What problem does it solve? Machine learning teams lose track of experiments, hyperparameters, and model versions when training runs are scattered across notebooks and scripts, making results hard to reproduce and compare. ## Core Features & Use Cases - Experiment Tracking: Log metrics, configs, media, and system stats from PyTorch, TensorFlow, Keras, HuggingFace, and PyTorch Lightning training loops with automatic real-time dashboards. - Hyperparameter Sweeps: Run grid, random, or Bayesian optimization searches with early termination and parallel agents across multiple GPUs. - Artifacts & Model Registry: Version datasets and models with lineage tracking, aliases like 'production', and a central registry for deployment governance. - Use Case: A team fine-tuning a BERT classifier can log every training run, launch a Bayesian sweep over learning rates and batch sizes, then promote the best checkpoint to a production model registry with full lineage back to the training dataset. ## Quick Start Initialize a W&B run in my training script, log the loss and accuracy each epoch, and save the final model as a versioned artifact.