The evolution of L7 proxies in microservices architecture has been marked by the emergence of smart RPC libraries, such as Finagle and Hystrix, which aimed to manage L7 communications but faced challenges in portability and maintenance. The introduction of Smart Proxies like SmartStack, Linkerd, and Envoy Proxy has addressed these issues, with Envoy Proxy being a notable pioneer in using dynamic APIs for management and having an ecosystem of control planes that use it. HAProxy and NGINX have responded by releasing their own versions with enhanced features, including runtime APIs and support for hitless reloads, but Envoy Proxy now holds the lead as the most popular and widely adopted L7 proxy solution.