On December 13th (2019) we organized a machine-learning workshop at the premises of the IAASARS/NOA, at Penteli (Greece). The goal of this particular workshop was to enhance the interaction between the researchers of the National Observatory of Athens and the Athena Research Center. The former presented challenges from their own fields of expertise (Astronomy, Seismology, Remote Sensing, Meteorology), while the later showcased tools and solutions for a wide range of applications. This long day of fruitful discussions has already initiated some collaborations and we are anticipating the results.