Boomf's Shopify store was built with a custom theme and app to offer personalized exploding cards and greeting cards. The custom Shopify app enables product personalization through images, messages, and add-ons, which are integrated with the production plant's PDF generator for order fulfillment. The development included a custom theme that passes parameters to the app and opens different instances based on the selected variant. Additionally, we successfully migrated 4 million users from a custom platform to Shopify.