To randomly create a time.Sleep in Golang you can use the code snippet below. You may want to simulate a load in your web server and have an arbitrary seconds or minutes before getting the reply.

package main

import (
	"log"
	"math/rand"
	"time"
)

func main() {
	rand.Seed(time.Now().UnixNano())
	for i := 0; i < 15; i++ {
		delta := rand.Intn(6 + 1)                      // randomly generates numbers 1 to 6
		time.Sleep(time.Duration(delta) * time.Second) // sleep and wait
		log.Printf(" - waited for %d second(s)\n", delta)
	}
}

Demo

demo-randomly-create-a-time-sleep-in-golang.gif