The First Rule of Machine Learning: Start Without Machine Learning
I recall attending a technical talk given by a team of senior ML scientists from a prestigious SV firm (that I shall not name here).  The talk was given to an audience of scientists at a leading university.The problem was estimating an incoming train speed from an embedded microphone sensor near the train station.  The ML scientists used the latest techniques in deep learning to process the acoustic time series.  The talk session was two hours long.  This project was their showcase.I guess no one in the prestigious ML team knew about the Doppler shift and its closed form expression.  Typically taught in a highschool physics class.  A simple formula that you can calculate by hand: no need for a GPU cluster.