Basic async invocation Java CompletableFuture.runAsync(() -> System.out.println("Hello async!")); for (int i=0; i<5; i++) { System.out.print("Hey! "); Thread.sleep(100); } // Hey! Hello async! // Hey! Hey! Hey! Hey! GoLang go fmt.Println("Hello async!") for i:=0; i<5; i++ { fmt.Print("Hey! ") time.Sleep(100 * time.Millisecond) } // Hey! Hello async! // Hey! Hey! Hey! Hey!