JOSM is a great editor for OpenStreenMap. It provides a rich set of functionality to allow its users a fluent way of managing data. Currently, some parts of the core of JOSM are not written efficiently and expose ambiguous GUI that could be improved to provide the users of JOSM more intuitive way of interacting with the application, and as the result, to make their workflow more productive. I propose to refactor the core elements within JOSM, like search, download dialogs and the main menu. I expect to remove redundancies in the code, fix the documentation and add new features.