It is not very clear how the result will be calculated. Will there be a private leaderboard? Or should we overfitting to the public one?
Indeed, can we ask the moderator your question?
Yes, as with all DrivenData competitions there is a public leaderboard and a private leaderboard. Winners are selected based on the best score on the private leaderboard (see the “Selecting Winners” section of the rules).
As always, it’s recommended to evaluate your models using best practices like holdout and cross-validation to ensure that you are not overfitting the training data or the public leaderboard.