QARM V2: Quantitative Alignment Multi-Modal Recommendation for Reasoning User Sequence Modeling
Tian Xia, Jiaqi Zhang, Yueyang Liu, Hongjian Dou, Tingya Yin, Jiangxia Cao, Xulei Liang, Tianlu Xie, Lihao Liu, Xiang Chen, Shen Wang, Changxin Lao, Haixiang Gan, Jinkai Yu, Keting Cen, Lu Hao, Xu Zhang, Qiqiang Zhong, Zhongbo Sun, Yiyu Wang, Shuang Yang, Mingxin Wen, Xiangyu Wu, Shaoguo Liu, Tingting Gao, Zhaojie Liu, Han Li, Kun Gai
TL;DR
QARM V2 tackles the limitations of ID-based industrial RecSys by aligning LLM-derived semantic signals with business objectives for lifelong user sequence modeling. It introduces reasoning-based item alignment and a Res-KmeansFSQ hybrid quantization to generate both embeddings for GSU and multi-level Semantic IDs for ESU, enabling end-to-end optimization. Empirical results across multiple industrial domains show consistent offline improvements in AUC/GAUC and notable online gains in revenue, GMV, and engagement, validating the approach's practical impact. The work demonstrates that business-aware LLM representations can significantly enhance both retrieval and ranking in real-world, long-tail, multi-modal recsys ecosystems.
Abstract
With the evolution of large language models (LLMs), there is growing interest in leveraging their rich semantic understanding to enhance industrial recommendation systems (RecSys). Traditional RecSys relies on ID-based embeddings for user sequence modeling in the General Search Unit (GSU) and Exact Search Unit (ESU) paradigm, which suffers from low information density, knowledge isolation, and weak generalization ability. While LLMs offer complementary strengths with dense semantic representations and strong generalization, directly applying LLM embeddings to RecSys faces critical challenges: representation unmatch with business objectives and representation unlearning end-to-end with downstream tasks. In this paper, we present QARM V2, a unified framework that bridges LLM semantic understanding with RecSys business requirements for user sequence modeling.
