step1.go

// Acts as our index page
func indexHandler(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte(`<a href="/home"> Click here to start a request </a>`))
}
func homeHandler(w http.ResponseWriter, r *http.Request) {
     w.Write([]byte("Request started"))
    go func() {
        http.Get("http://localhost:8080/async")
    }()
    http.Get("http://localhost:8080/service")
    time.Sleep(time.Duration(rand.Intn(200)) * time.Millisecond)
    w.Write([]byte("Request done!"))
}
// Mocks a service endpoint that makes a DB call
func serviceHandler(w http.ResponseWriter, r *http.Request) {
    // ...
    http.Get("http://localhost:8080/db")
    time.Sleep(time.Duration(rand.Intn(200)) * time.Millisecond)
    // ...
}
// Mocks a DB call
func dbHandler(w http.ResponseWriter, r *http.Request) {
    time.Sleep(time.Duration(rand.Intn(200)) * time.Millisecond)
    // here would be the actual call to a DB.
}