Monthly summary for 2026-05 - Apache Flink (repo: apache/flink) Key features delivered: - Dependency upgrades and BOM alignment: Upgraded core Java dependencies across modules for security and performance. Migrated Jackson dependencies to be inherited from the BOM to improve dependency management and reduce pin drift. Specific commits included upgrading log4j-core, jackson-bom, and assertj-core, plus netty BOM updates. This reduces maintenance burden and improves consistency across modules. - Code quality improvements and testing modernization: Enforced ESLint in runtime-web and migrated tests from JUnit4 to JUnit5 to modernize testing practices and improve code quality. - Job Overview DAG auto-fit and recenter control: Implemented auto-fit for the Job Overview DAG height based on window size and added a recenter control button to enhance user interaction with the graph. Major bugs fixed: - Applied hotfix to update Netty to 4.2.13.Final to address stability/security fixes and reduce risk from older transitive dependencies. - Dropped redundant Jackson version pins and inherited versions from BOM to avoid version conflicts and improve dependency resolution. - Fixed missing ESLint enforcement under runtime-web to ensure consistent code quality checks. Overall impact and accomplishments: - Improved security posture and runtime performance through updated dependencies and reduced pinning conflicts. - Enhanced developer experience and code quality via ESLint enforcement and JUnit5 migration. - Improved UI/UX for the Job Overview graph, enabling better analysis and quicker insight for operators. - Demonstrated robust dependency management, modernization of tests, and user-centric UI improvements, delivering measurable business value through stability, maintainability, and usability. Technologies/skills demonstrated: - Java dependency management and BOM-based versioning (log4j, jackson, netty, assertj) - Frontend testing modernization and linting (ESLint); Test framework migration (JUnit5) - UI enhancement for graph visualization (auto-fit, recenter control) - Build and release hygiene, hotfix management, and risk reduction through targeted dependency updates