Ruby on Rails is a server-side web application framework, which is a software framework used to develop web applications and APIs. A Ruby developer is a backend software developer, which means they create the databases, libraries, and logic that make up an application. In this career, you use Ruby on Rails, along with other programming frameworks and languages, to make the applications scalable. Your duties are to script new applications or maintain and improve existing ones. Your responsibilities on a given project require you to work closely with frontend development teams to ensure that the visual interface features of the application work in tandem with your code.