This talk illustrates the development techniques, Ruby patterns and best practices we adopt at DNSimple to develop new features and ensure long-term maintainability of our codebase. It also features how we used Lotus to develop the new API as a standalone Rack app mounted under the Rails router. Two years ago we started a major redesign of our REST API with the goal to decouple it from our main Rails application and expose all the main features via API. It was not a trivial task, but still feasible due to the guidelines we adopted in the last 6 years to structure our Rails application.