Worked on deployment reliability and security improvements in the aws-greengrass-nucleus repository, focusing on IoT credential endpoint validation and deployment status reporting. Developed a preflight validator to ensure deployments only proceed after credential verification, introducing configurable timeouts and robust error handling in Java. Enhanced deployment workflows by adding MQTT-based status reporting for endpoint-switch deployments, improving operational visibility and state management. Addressed concurrency issues and job deduplication in aws-greengrass-lite using C and backend development skills, preventing deployment stalls and ensuring idempotent updates. The work demonstrated depth in embedded systems, AWS IoT, and testing, resulting in more resilient and observable deployment processes.