Looks like this article is over a year old, so some of the technical solutions or opinions may be a bit outdated now.

DesignKarma is a longtime Development Partner for Craft CMS, and today Craft announced a first-party Shopify integration, making it easier than ever to start selling products with Craft.

The new Shopify plugin is another great addition to the Craft plugin store, and gives clients another option for handling e-commerce with Craft. DesignKarma has previously used the excellent Craft Commerce plugin ($299 for the "Pro" version), but the new free plugin allows Craft developers to quickly and seamlessly integrate with existing Shopify stores. Just in time for Christmas too!