It is. We'll start from a simple Symfony Microkernel application. Then change the Kernel to use Controllers as Commands and build classes to serve Data and Interaction to endpoints. Then we'll create tests for logic and behavior. Then we'll create more routes. Then we'll connect to a database. Then we'll improve it more. The intention is not to show "how to build an API from scratch" but evolve a Symfony Microkernel project as a Flexible Framework and explore more possibilities using Command pattern to split HTTP logic from business logic.