there's also a blended style where you start with FDD then perform SDD in the refactoring. This way you're not performing blind architecture - you make the necessary change and you systematise the solution during refactoring, if it is a change in system behaviour. You can use this technique on an ongoing basis at a per-ticket scale and trust that you are 1. not violating YAGNI and 2. always in a state of minimum-viable-well-designed-architecture.