During September 2025, Greenwd enhanced the smithy-lang/smithy-rs repository by developing a feature for aws-smithy-mocks that enables dynamic mocked response computation in the RuleBuilder component. By introducing the then_compute_output method, Greenwd allowed mocked outputs to be derived directly from input request data, improving the realism and maintainability of test scenarios. The implementation included new unit tests to validate complex stubbing behaviors and comprehensive documentation updates. Working primarily in Rust and focusing on SDK development and mocking techniques, Greenwd’s contribution addressed the need for more accurate integration testing, reducing test churn and supporting faster feature validation within the codebase.