Roxana Neophytou enhanced backward compatibility testing for Cassandra SSTable formats in the apache/cassandra repository, focusing on serialization integrity between versions 3.0.25 and 3.11.11. She introduced legacy SSTable test data and developed methods to verify the behavior of frozen tuples and their removal across these versions, thereby expanding the coverage of cross-version testing. Her work leveraged Java, data structures, and file I/O to ensure that serialization changes did not break compatibility with older data formats. This targeted feature improved the reliability of Cassandra’s storage layer by systematically validating backward compatibility through comprehensive automated testing scenarios.