Justin developed and delivered an EMR CloudWatch Monitoring Integration for the aws/aws-cli repository, introducing a new configuration schema that enables Amazon EMR clusters to specify CloudWatch logging settings such as log group names, stream prefixes, encryption keys, and log types. He implemented this feature using Python, leveraging AWS CLI development skills and integrating with CloudWatch to enhance observability and governance for EMR workflows. The work included thorough unit testing and code review, ensuring stability and compatibility with existing systems. Justin’s contribution addressed the need for improved monitoring and incident response, demonstrating depth in schema design and cloud integration practices.