A notebook you can run

This is not a screenshot or a recorded video of a notebook: it is real Python, running inside your browser via WebAssembly (Pyodide), with nothing installed and no server behind it. The first load can take a few seconds to boot the interpreter and its libraries; after that, every cell runs on the fly.

The notebook builds a synthetic customer-churn dataset, trains a logistic regression with scikit-learn, and compares its ROC-AUC against a naive baseline, explained cell by cell. You can change any value and rerun it.