Ranking Websites in Real-time with Apache Kafka’s Streams API

Zalando, Europe's largest online fashion retailer, has developed an automated methodology to discover the next "best" fashion-related websites by using a modified version of Jon Kleinberg's HITS algorithm. The core concept in HITS is that of Hubs and Authorities, where a Hub points to lots of other good entities and an Authority is pointed to by lots of good entities. Zalando uses Apache Kafka's Streams API for real-time ranking of domains and building applications on top of it. This approach allows them to build scalable microservices that fit well into their existing deployment setup, stay close to the data, and solve important problems in their business domain.