Markus Kull worked on the debezium/debezium repository, focusing on upgrading the Cassandra 4 connector from version 4.0.2 to 4.1.8 to align with evolving dependencies. Using Java and Maven, Markus managed the upgrade process, ensuring no functional changes were introduced, and validated the integration through thorough testing. When issues surfaced with Cassandra 4.1.8, Markus executed a controlled rollback to 4.1.7, prioritizing data integrity and production stability. The work included detailed documentation and cross-team coordination, establishing a reliable rollback path and setting a precedent for future upgrades. This approach demonstrated careful dependency management and release engineering practices.