Learning effective feature crosses is the key behind building recommender systems. However, the sparse and large feature space requires exhaustive search to identify effective crosses. Deep & Cross Network (DCN) was proposed to automatically and efficiently learn bounded-degree predictive feature interactions. Unfortunately, in models that serve web-scale traffic with billions of training examples, DCN showed limited expressiveness in its cross network at learning more predictive feature interactions. Despite significant research progress made, many deep learning models in production still rely on traditional feed-forward neural networks to learn feature crosses inefficiently. In light of the pros/cons of DCN and existing feature interaction learning approaches, we propose an improved framework DCN-M to make DCN more practical in large-scale industrial settings. In a comprehensive experimental study with extensive hyper-parameter search and model tuning, we observed that DCN-M approaches outperform all the state-of-the-art algorithms on popular benchmark datasets. The improved DCN-M is more expressive yet remains cost efficient at feature interaction learning, especially when coupled with a mixture of low-rank architecture. DCN-M is simple, can be easily adopted as building blocks, and has delivered significant offline accuracy and online business metrics gains across many web-scale learning to rank systems.

在大规模工业应用中，我们提出了改进版DCN（DCN-V2）框架，以便更高效地学习特征交互。经广泛超参数搜索和模型调试等实验验证，改进版DCN-V2算法表现优于当今所有最新算法。该算法更具表现力，仍然具有成本效益，在低秩架构的混合耦合情况下，可用作构建块，并在Google的许多大规模学习排名系统中提高了离线精度和在线业务指标。

DCN V2: 改进的深度交叉网络与基于Web规模的排序学习系统实践经验