A person works with code to create what users can see and interact with is considered a front-end developer. They focus on how websites and applications look and how the user experiences them. A back-end web developer is a computer programmer who ensures that the website or app behaves the way that it should. The results of the back-end code are not usually directly seen by users. Instead, back-end development may include things like creating a database to store information like customer details or building out how the app will interact with different servers.