David Rousseau is senior scientist at IJCLab-Orsay, Université Paris-Saclay. After a dozen of years doing many things throughout ATLAS software, a chance meeting in 2013 with a Machine Learning (what was this?) computer scientist decided a new path in his career. He has set-up two HEP and Machine Learning competition on Kaggle and other platforms (HiggsML for classification, TrackML for tracking), co-created the ATLAS ML group and now is ATLAS contact in the Interexperiment Machine Learning group. He is also involved in Higgs physics, Higgs to tautau and now Higgs to four leptons.