The text discusses the use of GraphOS, a tool that enables building polyglot graphs by allowing new subgraphs to extend and override existing monoliths. The authors demonstrate how to add Rust to a GraphQL API using GraphOS, starting with creating a supergraph from an existing monolith, defining a new Rust subgraph, and overriding fields from the monolith using the `@override` directive. They also cover testing the entity resolver and deploying the subgraph to Apollo GraphOS, showcasing its benefits in enabling users to implement individual features in their preferred language without worrying about interoperability.