ASOS uses machine learning to recommend products to shoppers by analyzing their browsing history, past purchases, and the buying patterns of similar customers. The system delivers billions of product recommendations per day across the ASOS website and app.

ASOS's recommendation engine uses collaborative filtering — a technique that identifies patterns in how customers interact with products — to suggest items likely to appeal to individual shoppers. It also uses deep neural networks to classify products by attributes such as color, style, and occasion, enabling recommendations that go beyond similar items to suggest complementary ones that form complete outfits. The system is built on Microsoft Azure Machine Learning and processes data from the platform's full product catalog continuously.