Unless you seek really good real time system use NodeJS otherwise Go. I use NodeJS and MongoDB to handle upto 6k req/sec on two quad core server on AWS with ave

Unless you seek really good real time system use NodeJS otherwise Go. I use NodeJS and MongoDB to handle upto 6k req/sec on two quad core server on AWS with average latency time less than 60ms with each request hitting Mongo at least 2 times. New version of JS i.e. ES7 is way more productive than Golang syntax.