ZoRRO: A Zero-Weight Personalized Recommender System for Scalable News Recommendation
This work addresses the high training costs, substantial inference latency, and poor deployment scalability prevalent in large-scale news recommendation systems by proposing a training-free, zero-parameter personalized recommendation framework. The approach achieves personalization through efficient matching between user behavioral representations and news semantics, entirely circumventing neural network training or fine-tuning. Experimental results demonstrate that the method outperforms strong neural baselines in offline evaluations, while online A/B tests show click-through rates nearly on par with state-of-the-art models. Notably, it achieves over a 600× speedup in inference latency, offering compelling evidence of the often-overlooked discrepancy between offline metrics and online performance. To the best of our knowledge, this is the first practical news recommendation system that simultaneously delivers high performance and eliminates the need for model training.