A Back-End developer is responsible for creating a server-side application. Most server-side applications are consist of three main parts: A server, an application, and a database. The back-end development contains the behind the scene works and activities that the end-user doesn’t see but without them, there is no complex application. Back-end developers create the main application logic and present it as a web service or an API (Application Programming Interface) that used by front-end developers and others.
There are many things that back-end developers need to consider to create a high-performance application such as the proper architecture, database, design pattern, deployment methods, and etc.
So, turn on your espresso machine and start to code.