Comment by nasretdinov

Well, essentially Go doesn't have a separate async keyword because all goroutines run asynchronously under the hood. In the beginning the advised (and default) way of running Go code was GOMAXPROCS=1, essentially ensuring there is no actual parallelism, just asynchronous code. Since then, of course, around Go 1.5, the default switched to number of cores, making goroutines both async and parallel