Arkency-maintained reference repository (github.com/RailsEventStore/ecommerce) showcasing the layered DDD approach in the talk: a simple order-management system with no JavaScript, an ecommerce/ domain directory independent of Rails, processes coordinating domains, read models built from events, and tickets tagged 'good first issue'. Recommended as a sandbox to experiment with typical domains, processes and read models before applying the ideas to a client project. Future plans include reusing its domains in actual client projects and a Hanami port.