Developed and delivered a new Range Query API for sorted maps and sets within the moonbitlang/core repository, focusing on efficient data retrieval for analytics workloads. The work centered on implementing an inclusive range method that enables clients to extract subsets of data by keys or values directly from the data structures, reducing the need for client-side filtering and minimizing data transfer. Leveraging skills in algorithm implementation and data structures, the developer ensured seamless integration with existing APIs and maintained a robust, version-controlled codebase. The project was completed in mbt, with attention to clean API design and alignment with the broader scalability roadmap.