What problem does it solve? Training ML models on Databricks involves many failure-prone details: models landing in the deprecated workspace registry instead of Unity Catalog, Optuna trials each registering a new model version, training/serving skew from inconsistent feature computation, and serverless job submission traps that silently lose outputs. This Skill encodes the canonical train-register-score flow so models are trained remotely, registered correctly, and consumed as batch UDFs or real-time endpoints. ## Core Features & Use Cases - Train and register with MLflow: XGBoost, scikit-learn, LightGBM, and PyTorch with autolog, Optuna hyperparameter search as nested runs, UC registration, and @prod/@challenger alias management. - Batch and real-time consumption: Score Delta tables via spark_udf into gold prediction tables, or hand off to model serving endpoints for sub-100ms inference. - Feature Store and Feature Views: FeatureLookup with point-in-time joins, fe.score_batch for feature-backed models, declarative Feature Views with rolling windows, Lakebase online store, and streaming Kafka features. - Custom models and agents: File-based custom PyFunc models and LangGraph ResponsesAgent with UC Function and Vector Search tools. - Use Case: Train a turbine failure classifier on silver telemetry tables as a serverless job, register it to Unity Catalog under the @prod alias, and write daily risk scores to a gold predictions table read by dashboards. ## Quick Start Use the databricks-ml-training skill to train an XGBoost classifier on my silver features table, register it to Unity Catalog, and score the latest data into a gold predictions table.