An Application Frameworks developer designs and implements software frameworks that facilitate application development. They provide a foundation and set standards for coding, reducing the need for coding from scratch. They are responsible for developing, maintaining, and improving the framework, ensuring it's user-friendly and efficient. They often work with other developers, providing them with tools and libraries to build applications more efficiently. They may also be responsible for troubleshooting, fixing bugs, and improving the performance of the framework. Additionally, they may provide documentation and training to other developers on how to effectively use the framework.