Vercel express server

package.json

{
  "name": "something",
  "version": "2.2.0",
  "description": "",
  "main": "index.js",
  "dependencies": {
    "ejs": "^3.1.5",
    "express": "^4.17.1",
    "helmet": "^4.2.0"
  },
  "keywords": [],
  "author": "",
  "license": "ISC"
}

server.js

const path = require('path')
const express = require('express')
const app = express()
const helmet = require('helmet')

const viewsPath = path.join(__dirname, './views')
app.set('view engine', 'ejs')
app.set('views', viewsPath)
app.disable('x-powered-by')
app.use(helmet())

app.get('/', async (req, res) => {
  res.render('index.ejs', { data: data.default })
})

app.listen(3000)

module.exports = app

vercel.json

{
  "version": 2,
  "builds": [
    {
      "src": "index.js",
      "use": "@now/node-server"
    },
    {
      "src": "/public/*",
      "use": "@vercel/static"
    }
  ],
  "routes": [
    { "handle": "filesystem" },
    { "src": "/.*", "dest": "index.js"}
  ]
}