They sent a codility test, with three assignments, needed to be done in around 3 hours. One of them was about k-NN from scratch, another was to implement different regularization methods with scikit learn (Lasso, RIdge, ElasticNet), and the third one was a bit complicated task related to different strings. I passed all the tests correctly, and then we made a 15 mins call. It was about introducing yourself etc., nothing special. They didnt proceed with me after this point, but I think they really prefered someone with experience in 3D and simulations. They sent a final rejection 3-4 weeks after the last meeting.