This disclosure describes systems, devices, and computer-implemented methods that facilitate the modification of network configuration data within a client network to improve a Quality of Experience (QoE) metric associated with the execution of a user application on a client device. More specifically, a diagnostic controller may retrieve diagnostic data associated with the execution of a user application on a client device, determine a QoE metric associated with the execution of the user application, and generate network configuration data for delivery to the client device that improves the QoE metric, based on the diagnostic data and the QoE metric.