For online publications and media sites, recommendation systems play an important role in engaging readers. At Chartbeat, we are actively developing a recommendation system that caters to billions of daily pageviews across thousands of global websites. While conventional discussions frequently highlight the data science and machine learning facets of the system, the cornerstone of a successful application is its system architecture. In this presentation, we will dissect our architectural decisions designed to meet high-performance requirements and share insights gleaned from our journey in scaling up the recommendation system.