This gist shows the impact of resolving fields in parallel in graphql-go.

main.go

package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"

	"github.com/graphql-go/graphql"
)

func main() {
	// Schema
	fields := graphql.Fields{
		"hello": &graphql.Field{
			Type: graphql.String,
			Resolve: func(p graphql.ResolveParams) (interface{}, error) {
				http.Get("http://fake-response.appspot.com/?sleep=2")
				return "world", nil
			},
		},
	}
	rootQuery := graphql.ObjectConfig{Name: "RootQuery", Fields: fields}
	schemaConfig := graphql.SchemaConfig{Query: graphql.NewObject(rootQuery)}
	schema, err := graphql.NewSchema(schemaConfig)
	if err != nil {
		log.Fatalf("failed to create new schema, error: %v", err)
	}

	// Query
	query := `
		{
			a: hello
			b: hello
			c: hello
			d: hello
			e: hello
		}
	`
	params := graphql.Params{Schema: schema, RequestString: query}
	r := graphql.Do(params)
	if len(r.Errors) > 0 {
		log.Fatalf("failed to execute graphql operation, errors: %+v", r.Errors)
	}
	rJSON, _ := json.Marshal(r)
	fmt.Printf("%s \n", rJSON) // {“data”:{“hello”:”world”}}
}

run.sh

> go build && time ./hello-world
{"data":{"a":"world","b":"world","c":"world","d":"world","e":"world"}}
./hello-world  0.01s user 0.01s system 0% cpu 2.617 total