Worked on the facebook/sapling repository to deliver Cloud Environment Variant Detection for HPC Kubernetes, enhancing environment awareness and enabling safer cloud-based deployments. Developed a new Env::Cloud variant in Rust, aligning with existing thrift types and updating hostcaps to export cloud-host signals. Implemented dual detection logic in backend systems, using both hostname schemes and environment variables to reliably distinguish between production and cloud environments, including edge cases during pod startup and mount operations. This feature improved explicit prod-or-cloud semantics and prepared the codebase for broader cloud-scale adoption, demonstrating backend development skills and a focus on robust, maintainable infrastructure enhancements.