Developed an advanced nested variable interpolation feature for the containers/podman-compose repository, enabling Compose-compatible configuration parsing with support for alternative values and deep nesting. Leveraged Python and regular expressions, but moved beyond regex-based approaches by implementing a lookahead parsing engine to accurately handle complex nested structures. This work aligned closely with the Compose specification, ensuring consistent behavior across different environments and reducing manual configuration overhead for users. Emphasized maintainability and traceability through clear commit messages and comprehensive code comments, while also laying the foundation for expanded unit testing to cover edge cases in variable interpolation and configuration management.