To personalize an ecommerce site, finding the right balance between performance and personalization can be challenging. One approach is to use a hybrid framework like Next.js that supports both statically and dynamically rendered pages. However, this can lead to slower page loads and suboptimal user experience. A better solution is to use Netlify Edge Functions, which allow you to execute arbitrary code at the edge of the network. By creating a middleware function with Builder.io's React SDK, you can personalize your site by rewriting URLs based on query parameters and targeting specific audiences. With this approach, you can create personalized pages using Builder.io's Visual Editor, set up custom targeting attributes, and deploy the site to Netlify for a performant and scalable ecommerce experience.