This is an excellent refactoring story using one of Shopify’s core classes.

As you can imagine, one of the most critical areas in Shopify’s Ruby on Rails codebase is the Shop model. Shop is a hefty class with well over 3000 lines of code, and its responsibilities are numerous. When Shopify was a smaller company with a smaller codebase, Shop’s purpose was clearer: it represented an online store hosted on our platform. Today, Shopify is far more complex, and the business intentions of the Shop model are murkier. It can be described as a God Object: a class that knows and does too much.

They use Martin Fowler’s Strangler Fig pattern to achieve the refactoring. You may recall we discussed this on our episode with Amal Hussein.