Developed hierarchical PartitionKeys support for Azure Cosmos DB within the azure-sdk-for-go repository, enabling more advanced and scalable data partitioning strategies for users. This work involved designing and implementing new APIs in Go to create and manage hierarchical PartitionKeys, expanding the SDK’s flexibility for complex data models. The approach included comprehensive testing to validate functionality, error handling, and edge cases, ensuring reliability for production environments. Leveraging expertise in API development, Azure Cosmos DB, and data partitioning, the developer focused on robust code quality and maintainability. No bug fixes were recorded during this period, with efforts concentrated on this core feature enhancement.