Developed a new feature for the docker/envoy repository that introduces the x-envoy-compression-status response header within the Envoy compressor filter. This enhancement provides explicit information on whether a response was compressed and, if not, details the reason compression was skipped, thereby improving observability and troubleshooting for users. The implementation is controlled by the envoy.reloadable_features.compressor_add_status_header runtime guard to ensure backward compatibility when disabled. The work leveraged C++, YAML, and protobuf, and involved skills in compression, configuration management, and HTTP filters. No bugs were fixed during this period, with the focus placed on delivering this targeted functionality and comprehensive documentation.