Thiago Mendes developed server-side JSON response support for the modelcontextprotocol/rust-sdk repository, focusing on stateless mode enhancements. He introduced a json_response option within StreamableHttpServerConfig, allowing the server to return application/json instead of text/event-stream, which reduced overhead for simple request-response patterns. Using Rust and leveraging backend and API development skills, Thiago aligned the implementation with SEP-1442 goals and maintained backward compatibility. His work delivered measurable performance improvements, including lower latency and higher throughput under load. He also addressed stability and concurrency in testing, ensuring the new feature operated reliably and efficiently in high-concurrency, production-like environments.