Developed and delivered a new User Defined Function called split_part for the Reasoner module in the OpenSPG/openspg repository, enabling flexible string splitting by a separator with support for negative indices to retrieve elements from the end of the split string. Applied Java and backend development skills to implement the feature, focusing on robust handling of various input scenarios. Emphasized test-driven development by creating comprehensive unit tests that cover multiple edge cases, ensuring correctness and regression safety. The work enhanced data extraction and string manipulation capabilities in query expressions, contributing to more reliable and flexible backend data processing workflows.