An AppDynamics developer is responsible for implementing and managing the AppDynamics software, which monitors system performance and troubleshoots issues. They design and set up application performance management (APM) tools in line with business needs, allowing for real-time monitoring of applications, servers, databases and networks. They also work to identify performance bottlenecks, slow transactions, and other issues that could impact user experience or business outcomes. Additionally, they assist with capacity planning, system optimization, and creating detailed reports for stakeholders. It's a role that requires a strong understanding of both IT infrastructure and business processes.