Had to write a router software once in Java back in 2014. The past experience in me believed that its not a good choice to use something with stop the world GCs for routers. The goal was to have everything under 1ms (max 2ms in rare cases). It has http server on head and websocket connections on the tail end. Turns out the class instantiations and JSON parsing were a bottleneck. Thread safe resources were valuable, the libraries which did not had thread safe resources were re-written to support what we needed. The http server was re-written barebones, the JSON parsing was re-written with barebones. And it worked.