Hieu Sy Do developed the Dynamic Modules SSL Attribute Expansion feature for the envoyproxy/envoy repository, enabling dynamic modules to access and expose detailed TLS connection metadata such as TLS version, certificate details, and Subject Alternative Names. This work involved updating the ABI and introducing new getters in the filter callback, allowing for more granular inspection and policy-driven control of SSL connections. Using C++ and leveraging expertise in API design and SSL/TLS, Hieu focused on enhancing observability and security policy flexibility for network traffic. The feature addressed the need for deeper diagnosability and control within Envoy’s dynamic module architecture.