Somewhere in the DataLens build, my teammate and I hit the wall every "zero-dependency" project eventually hits: the anomaly detector needed a neural net, and the rulebook said no third-party packages. No NumPy. No pandas. No scikit-learn. Just Python 3.14's standard library. Our first reaction was denial. You cannot build an ANN without a matrix library — everyone knows that. numpy.dot() is basically load-bearing infrastructure for machine learning in Python. We spent an embarrassing amoun...