Worked on the hivemq-community-edition repository to enhance MQTT message processing by implementing a pre-validation step for maximum packet size within the MQTTMessageDecoder. This approach allowed the system to efficiently skip unnecessary reads for oversized packets, reducing CPU and memory usage under load while improving throughput. The refactor also introduced more robust error handling and defensive parsing, strengthening resilience against malformed packets. Using Java and leveraging expertise in network programming and protocol implementation, the work focused on optimizing the decoding path for both efficiency and safety. The contribution addressed a core aspect of MQTT protocol handling, improving overall system stability.