We are trying to build a high transactions per second, lower latency application using uWS. In this app, replies to http requests cannot be sent in the request callback as the server needs to consult other external systems to get the response. Hence, we have architect-ed the server to post responses to the uws loop via Loop::defer. The throughput of the system reduces drastically when we do that however. For example, the simple server below can handle 190,000 requests per second in a laptop.