Developed MQTT plugin support with OpenTelemetry instrumentation for the alibaba/loongsuite-go-agent repository, focusing on enhancing observability in publish and delivery flows. The work involved implementing new data types for publish and delivery requests and integrating tracing attributes directly into the MQTT protocol. Using Go as the primary language, the developer leveraged backend development skills and OpenTelemetry to enable end-to-end tracing, which improves debugging and supports better service level agreement adherence. This feature lays the foundation for future plugin extensibility and provides a more robust framework for monitoring message flows, contributing to a more maintainable and observable backend system.