Ferenc Csaky upgraded the Flink dependency to version 1.20 across the apache/flink-cdc repository, focusing on test bases and serializer tests to ensure downstream compatibility with the latest Flink release. He updated Java imports to align with the new API while deliberately preserving existing business logic, minimizing disruption for users and integrations. His approach emphasized build management and thorough testing, validating that core functionality remained stable throughout the upgrade. By maintaining compatibility and reducing upgrade friction, Ferenc’s work enabled smoother transitions for downstream projects relying on Flink CDC, demonstrating careful attention to both technical detail and user impact within the codebase.