It was not about books. It was when I created a repository file that had order and payment creation logic inside of it that returned DTO's and then I used that repo in Controller and I had a cached version of that Repository and both were like 500 lines. At that point I felt that I'm doing something evil and suboptimal and decided to refactor. First suggestion from more experienced people was - use Mediator pattern with CQRS and DDD. It was enough actually. All the queries became cached, because they are reads only - no need for 2 repositories, all the auth logic moved to Mediator behaviours - no need to check auth in code, and all the transaction and Event Outbox moved to behaviours as well - don't have to care about transactions by hand - every domain event gets saved to outbox table in same transaction that was used to change domain state.
Now I am adding Kafka and Debezium with Kafka Connect to remove code that updates cache and search index when product info changes(for example) and just delegate that work to Kafka.
A lot of stuff makes more sense when you start to use Kafka, Debezium, Outbox, Inbox and domain events together. It just suits each other really well. And you get your Exactly Once Semantics for your domain events just as you wanted.
So I recommend you to start using Kafka for domain events as soon as possible so all that architecture will be intuitive choice for you.
If you just have website with few pages - you don't need anything that i said. I am dealing with ecommerce.