MALLORN Astronomical Classification — 4th Place

4th place / 894 teams, Top 0.5% (private LB F1 = 0.6684). Binary classification of Tidal Disruption Events (TDE) vs. non-TDE nuclear transients from simulated LSST lightcurves with extreme class imbalance (~4.8% TDE). Pipeline: Bazin exponential fit parameters + 80+ hand-engineered photometric features → XGBoost + adversarial validation for train/test distribution alignment.