During February 2026, João Guimarães focused on backend reliability improvements for the CopilotKit/CopilotKit repository. He addressed a bug in the LangGraphAgent component by implementing logic in TypeScript to clean up stale message state when events are suppressed. This change ensured that emit-messages-enabled nodes no longer retained outdated records, preventing cross-run contamination and improving the correctness of event handling. By targeting the messagesInProcess data structure, João enhanced system stability and reduced the risk of stale data affecting active nodes. His work demonstrated a careful approach to backend development, emphasizing robust event processing and maintainable code in a TypeScript environment.