**Learn to build robust, resilient, and highly maintainable cloud-native Java applications with hexagonal architecture and Quarkus ** Key FeaturesUse hexagonal architecture to increase maintainability and reduce technical debtLearn how to build systems that are easy to change and understandLeverage Quarkus to create modern cloud-native applicationsPurchase of the print or Kindle book includes a free PDF eBookBook DescriptionWe live in a fast-evolving world with new technologies emerging every day, where enterprises are constantly changing in an unending quest to be more profitable. So, the question arises — how to develop software capable of handling a high level of unpredictability. With this question in mind, this book explores how the hexagonal architecture can help build robust, change-tolerable, maintainable, and cloud-native applications that can meet the needs of enterprises seeking to increase their profits while dealing with uncertainties. This book starts by uncovering the secrets of the hexagonal architecture’s building blocks, such as entities, use cases, ports, and adapters. You’ll learn how to assemble business code in the domain hexagon, create features with ports and use cases in the application hexagon, and make your software compatible with different technologies by employing adapters in the framework hexagon. In this new edition, you’ll learn about the differences between a hexagonal and layered architecture and how to apply SOLID principles while developing a hexagonal system based on a real-world scenario. Finally, you’ll get to grips with using Quarkus to turn your hexagonal application into a cloud-native system. By the end of this book, you’ll be able to develop robust, flexible, and maintainable systems that will stand the test of time. What you will learnApply SOLID principles to the hexagonal architectureAssemble business rules algorithms using the specified design patternCombine domain-driven design techniques with hexagonal principles to create powerful domain modelsEmploy adapters to enable system compatibility with various protocols such as REST, gRPC, and WebSocketCreate a module and package structure based on hexagonal principlesUse Java modules to enforce dependency inversion and ensure software component isolationImplement Quarkus DI to manage the life cycle of input and output portsWho this book is forThis book is for software architects and Java developers looking to improve code maintainability and enhance productivity with an architecture that allows changes in technology without compromising business logic. Intermediate knowledge of the Java programming language and familiarity with Jakarta EE will help you to get the most out of this book. Table of ContentsWhy Hexagonal Architecture?Wrapping Business Rules inside Domain HexagonHandling Behavior with Ports and Uses CasesCreating Adapters to Interact with the Outside WorldExploring the Nature of Driving and Driven OperationsBuilding the Domain HexagonBuilding the Application HexagonBuilding the Framework HexagonApplying Dependency Inversion with Java ModulesAdding Quarkus to a Modularized Hexagonal ApplicationLeveraging CDI Beans to Manage Ports and Use CasesUsing RESTEasy Reactive to Implement Input A