Bernard developed a new configuration option for Envoy external authorization providers in the istio/api repository, enabling automatic clearing of the route cache when authorization settings change for both HTTP and gRPC providers. He introduced the clear_route_cache option and corresponding Protocol Buffers support, ensuring that routing decisions remain accurate as policies evolve. Working primarily in Go and Protocol Buffers, Bernard focused on API development and configuration management to address the need for consistent policy enforcement. The feature was implemented with attention to integration and maintainability, reflecting a targeted engineering effort over the course of one month without addressing bug fixes.