Backend developers are professionals who focus on the server side of web applications. They create and maintain the systems that process data and ensure that everything runs smoothly behind the scenes. This includes working with databases, server logic, and application programming interfaces (APIs) to connect the frontend of a website with the backend. These developers typically use programming languages such as Python, Java, or Ruby to build the functionality of a website. They also work with frameworks and tools that help manage data and server operations. Their role is crucial for ensuring that users have a seamless experience when interacting with a website or application.