March 29, 2019
Web browsers limit the number of active connections for each domain, but browsers distinguish domains by name rather than by IP address. Domain sharding, in which content is split across multiple subdomains, may drastically improve the user experience of slow page load times for image-heavy pages, but only if your server has sufficient bandwidth. Uploading content to Amazon S3 and using CloudFront to serve images from multiple subdomains has been shown to be an effective way to use domain sharding. In addition, when images are uploaded to S3, a Node.js script is triggered which creates thumbnails and the larger web versions of the full sized, high resolution images. The final step happens during the creation of a WordPress custom post type, where the domain sharding is actually applied.