express.js

const Express = require('express')

const app = Express()

const sleep = timeout => new Promise(resolve => setTimeout(resolve, timeout))

async function getData () {
  await sleep(400)

  return 1
}

async function processData (data) {
  await sleep(200)

  return data * 2
}

app.get('/', async function (request, reply) {
  const data = await getData()
  const processed = await processData(data)
  return processed
})

app.listen(3000, err => {
  console.log(err || 'listening...')
})