Several Java consultancies (e.g., Baeldung Pro, InfoQ, and O’Reilly) released time-limited free PDFs during the 2021 "Software Architecture Summit."

: The book is published by Packt Publishing , which often offers a free PDF eBook if you purchase the print or Kindle version.

Before downloading the PDF, let’s understand why this architecture exploded in popularity around 2020-2021.

:

com.mybankapp/ ├── domain/ (No dependencies) │ ├── model/ (Account, Customer) │ └── exception/ (DomainRuleViolation) ├── application/ (Use cases & Ports) │ ├── port/in/ (Input ports: CreateAccountUseCase) │ ├── port/out/ (Output ports: LoadAccountPort) │ └── service/ (Implements the Use Cases) ├── infrastructure/ (Adapters) │ ├── web/ (RestControllers) │ ├── persistence/ (JPA Repositories) │ └── messaging/ (Kafka/RabbitMQ listeners) └── shared/ (Helpers, Annotations)