Finds and remove duplicates from MongoDB without aggregation

MongoRemoveDupes.js

const devs = {};
    Device.find({}, (err, devices) => {
      devices.forEach((device) => {
        if (!devs || !devs[device.uid]) {
          devs[device.uid] = [];
        }
        devs[device.uid].push(device);
      });

      const dupesOnly = {};
      Object.keys(devs).forEach((key) => {
        if (devs[key].length > 1) {
          dupesOnly[key] = devs[key];
          console.log(`Keeping ${devs[key][0]._id} and Removing ${devs[key][1]._id}!`);
          Device.findByIdAndRemove({ _id: devs[key][1]._id }, (err3) => {
            if (err3) {
              console.error(err3);
            }
          });
        }
      });

      // const dupesOnly = Object.keys(devs).filter(dev => dev.length > 1);
      fs.writeFileSync('./devsDups.json', JSON.stringify(dupesOnly, '\t', 2), 'utf8');

Finds and remove duplicates from MongoDB without aggregation (it wasn't available to me)