Worked on stabilizing the Java-to-Swift translation pipeline in the swiftlang/swift-java repository by addressing error handling for unmapped JavaObject classes. Introduced a fail-fast mechanism in Swift that explicitly throws errors when a Java class lacks a corresponding Swift mapping, preventing runtime crashes and reducing debugging time. Developed and integrated targeted tests to validate translation behavior for missing mappings, ensuring ongoing regression coverage. This approach improved the reliability of the translation process and provided clearer developer feedback, ultimately lowering post-deployment support costs. The work demonstrated a focus on robust error handling, thorough testing, and practical use of Swift for cross-language integration.