Over a two-month period, contributed backend development work to the spree/spree repository, focusing on user profile management and shipment processing features using Ruby and Ruby on Rails. Delivered an update to the user profile API, enabling users to change their email addresses and simplifying the interface by removing unused parameters, which improved data integrity and reduced support overhead. Additionally, implemented a shipment item quantity calculation feature that aggregates quantities across line items, enhancing inventory planning and fulfillment accuracy. Emphasized robust test coverage and code refactoring throughout, demonstrating attention to API design, parameter handling, and maintainability within a production Rails environment.