During March 2026, Dmitry Tsulik developed a Docker Build System feature for the aws/aws-sam-cli repository, enabling users to specify custom image names with accurate tag and build-arg handling. He focused on expanding unit test coverage, addressing edge cases in image naming to ensure reliability and consistency across deployment environments. Working primarily in Python and leveraging Docker, Dmitry’s approach emphasized robust testing rather than bug fixes, resulting in a well-validated feature. His contributions included review-friendly, co-authored commits, reflecting a collaborative workflow. The work demonstrated depth in both implementation and validation, improving the flexibility and reliability of Docker-based build processes.