During their two-month contribution to the envoyproxy/envoy repository, Hyuan developed two security-focused features using C++, Protocol Buffers, and WebAssembly. In October 2025, Hyuan implemented a cryptographic signing capability for Envoy’s Wasm runtime, enabling Wasm modules to generate signatures with private keys and supporting key management utilities. In February 2026, Hyuan delivered OAuth2 client TLS mutual authentication, allowing certificate-based client authentication and improving OAuth2 deployment security. Both features included comprehensive documentation and unit tests, reflecting a methodical approach to secure API development. Hyuan’s work demonstrated depth in cryptography, mTLS, and protocol integration, addressing real-world security requirements in Envoy.