Shopify

Shopify, Inc. operates a cloud-based commerce platform designed for small and medium-sized businesses. Its software is used by merchants to run business across all sales channels, including web, tablet and mobile storefronts, social media storefronts, and brick-and-mortar and pop-up shops.

With quality articles posted weekly, Shopify's blog is top tier. Its well organized and the articles can go extremely deep. Couldn't find the RSS feed though