Client side A/B Testing and Personalization can significantly delay critical loading metrics—especially on mobile devices. Server side solutions, running at the origin, limit caching and remove many of the security and scalability benefits of the Jamstack. The recent arrival of edge compute provides a third option: modifying cached content directly at the CDN’s edge. This new architecture promises to reconcile tradeoffs between dynamic content and fast load times, opening a new paradigm for optimizing e-commerce sites.