During November 2024, Pimi contributed to the azure-sdk-for-go repository by implementing hierarchical PartitionKeys support for Azure Cosmos DB. This work involved designing and developing new APIs in Go to enable the creation and management of hierarchical PartitionKeys, allowing for more flexible and scalable data partitioning strategies. Pimi focused on robust API development and data partitioning logic, ensuring the feature addressed both common and edge case scenarios. Comprehensive tests were written to validate functionality and error handling, supporting production reliability. The depth of the implementation demonstrated a strong grasp of Go, Azure Cosmos DB internals, and advanced partitioning techniques.