.Layer is a data science oriented community created for promoting collaboration and knowledge sharing among its members. In Unix-like operating systems, files and folders starting with a dot are treated as hidden, invisible to the passerby. Most people don’t even know their existence and purpose. In a world where people produce data and live the outcomes of many performing algorithms, data scientists form, much like dot files, a hidden layer working behind the scenes. Now is the time that we, data scientists, say: Hello, World!