What he probably means ( he doesn't go into details), is that you can create a simple monolith without splitting up everything. Which is basically true. But a

What he probably means ( he doesn't go into details), is that you can create a simple monolith without splitting up everything. Which is basically true. But as soon as you go more complex, you'll probably wish you'd used DDD from the start. DDD is gaining traction, not because it's good. But because it's compatible with microservices. As an aside, i also like how jgobard developped ContosoUniversity ( https://github.com/jbogard/ContosoUniversityDotNetCore https://github.com/jbogard/ContosoUniversityDotNetCore / https://github.com/jbogard/ContosoUniversity/tree/master/src/ContosoUniversity https://github.com/jbogard/ContosoUniversity/tree/master/src... ) with vertical slices and feature folders.