During November 2024, Andrey Gubichev developed a customizable query optimization hints framework for the xupefei/spark repository, focusing on aggregate, sort, and window operators. He designed an abstract hint mechanism for aggregates and introduced an extension API to support custom hint resolution rules, enabling greater flexibility in guiding the optimizer and execution planning. By allowing hints on Sort and Window nodes, Andrey’s work improved the configurability and extensibility of Spark’s optimizer, laying groundwork for future performance enhancements. The implementation leveraged Scala, SQL, and Spark, demonstrating depth in both architectural design and practical integration without addressing bug fixes in this period.