This document discusses using ReactPHP as an event-driven and non-blocking I/O HTTP server with Symfony, a request-response PHP framework. ReactPHP runs the application event loop and handles requests without bootstrap code on each request, improving performance. Symfony is lightweight and supports modern practices. Benchmarks show ReactPHP with Symfony is faster than the default Symfony configuration with Apache and PHP-FPM. Some challenges are memory management, file uploads, and database interactions in long-running processes.