Shopify is a subscription-based software-as-a-service (SaaS) sales platform.
Backend::
Shopify uses Ruby on Rails, MySQL, Redis, and memcached for its backend system. It also uses Go and Lua for performance critical for backend parts.
Frontend::
Shopify uses React with GraphQL APIs for its frontend.
Shopify pod:
A Shopify pod contains data for one to many shops. It’s a complete version of Shopify that can run anywhere in the world.
Theme architecture::
A Shopify theme controls the style, organization, and features of a merchant’s online store.