Simple callback without nesting (no callback hell yet.)

simple_callback.js

function passMeCallback(options, callback) {
  //do something
  const err = null;
  const result = options;//some data goes here
  return callback(err, result);
}

passMeCallback({ age: 30 }, function(err, result) {
  console.log(result); //this will be the options we just passed to the function
});