oh javascript, how you nest so deeply, so easily...

gistfile1.js

function createCardsViaProvider(req, res, next) {
  var board = req.board;
  var handler = providers[req.params.provider].cardHandler;

  var promises = [];
  Column.findOne({ board: board._id, role: 1 })
  .exec(function (err, column) {
    if (err) {
      logger.error(err.message);
      res.send(500);
    } else {
      handler.batchImport(board, req.body, function (attributes) {
        attributes.column = column._id;
        promises.push(Card.create(attributes))
      }, function() {
        Promise.all(promises).then(function () {
          Board.update({ _id: board._id }, { columns: board.columns }, function(err) {
            if (err) { res.send(500, err.message); }
            else {
              Board.findOne({ _id: req.params._id }).populate('columns').exec(function(err, board) {
                if (err) {
                  logger.error(err.message)
                  res.send(500)
                } else if (board) {
                  Card.populate(board.columns, { path: 'cards' }, function(err) {
                    if (err) {
                      logger.error(err.message);
 /*lol javascript*/   res.send(500);
                    } else {
                      req.board = board;
                      res.send({ board: { columns: board.columns } })
                    }
                  });
                } else {
                  res.send(404);
                }
              });
            }
          });
        });
      })
    }
  })
};