Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for a conversation monitoring system. In one aspect, a method includes receiving a conversation stream generated from a conversation between a user of a platform and a current robotic agent, where the current robotic agent is one of a plurality of robotic agents servicing the platform; processing the conversation stream to identify characteristics of the conversation; extracting a conversation knowledge graph that includes a plurality of first nodes that each correspond a concept discussed in the conversation; identifying a state change in the conversation from the identified characteristics of the conversation; merging the conversation knowledge graph with a domain knowledge graph into a merged knowledge graph; and replacing the current robotic agent with a replacement robotic agent from the robotic agents, the replacement robotic agent selected based on the percentage matching value of the merged knowledge graph.