Andrew contributed to the sift-stack/sift repository by developing support for User Defined Functions (UDFs) and enhancing the User Group Management API. He designed and implemented new Protocol Buffer structures to define UDF inputs, outputs, and dependencies, and introduced an is_external flag to distinguish rule types. Using Python and gRPC, Andrew generated client and server stubs to extend user group, asset, and user management capabilities. His work focused on enabling rule-driven automation and improving governance, with clean, well-documented commits and no customer-facing incidents. The depth of his contributions reflects strong backend development and API design skills within a short timeframe.