Worked on the apache/spark repository to enhance data compatibility and maintain backward compatibility across Spark versions. Addressed Scala UDF support in Spark 4 by restoring Seq[Row] input handling, aligning behavior with Spark 3.5 to reduce upgrade friction for Scala users. Improved Spark SQL’s handling of UserDefinedTypes in columnar data sources by updating columnar getter methods, preventing runtime errors and enabling broader schema support. Expanded unit test coverage to validate these changes and ensure regression safety. Demonstrated expertise in Java, Scala, and Spark, with a focus on data processing, version compatibility, and robust open-source contribution workflows.