Java
Spring Transactions for Beginners: Make Database Changes All or Nothing
Learn Spring transactions step by step: build a JDBC checkout, observe real rollback, avoid proxy traps, and run 24 passing integration tests.
Artificial Intelligence
Spring and Physical AI for Beginners: Build a Tested Robot Mission Coordinator
A warehouse employee asks a robot to bring a parts bin to the packing station. The request sounds simple. The software has to answer several different questions: What does the employee mean? Is the destination allowed? Is the observation current? Did the robot accept the job? Did the bin actually Read more
Java
Domain-Driven Design with Spring for Beginners: From Business Rules to a Tested Application
Learn DDD with Spring through a complete ordering application: bounded contexts, aggregates, money, JPA, transactions, events, UML, BPMN and 32 passing tests.
Java
Spring Boot and Keycloak OIDC for Beginners: Login, Secure APIs, and Understand Every Step
Adding a login button to a Spring application is easy. Understanding what happens after someone clicks it takes a little more work. Who checks the password? Why are there several tokens? Why can a logged-in user still receive a 403? And why does an API need different security settings from Read more
Java
Spring Boot for Beginners: Build, Understand and Test Your First Java REST API
Learn Spring Boot step by step with a complete Java REST API, validation, JPA, transactions, 28 passing tests, UML and BPMN diagrams.
Artificial Intelligence
Design Patterns in Practice with Spring AI: The Advisor Pipeline
Build a Spring AI advisor pipeline with clear responsibilities, bounded retries and explicit ordering, verified by 20 tests through the real ChatClient.
Java
Spring Cloud Circuit Breaker in Practice: Resilient Calls Without Misleading Fallbacks
Build a Spring Cloud circuit breaker around a modern HTTP client, keep fallbacks honest, and verify failure and recovery with 18 integration tests.
Java
Spring, Spring Boot, Spring Modulith and DDD: A Beginner’s Guide to Your First Modular Application
You can build your first Spring endpoint in minutes. The harder question arrives when the application grows: where should the next piece of business logic live? This guide connects four ideas that are often introduced separately. Spring creates and connects application objects. Spring Boot supplies a convenient way to configure Read more
Best Practices
Spring Modulith and DDD: From Business Boundaries to Reliable Events
A package called orders does not become a bounded context just because its name sounds like the business. And an event called OrderConfirmed does not make an integration reliable just because a listener receives it on your laptop. The interesting direction in Spring Modulith is the connection between these two Read more
Best Practices
Your Modular Monolith Needs an Architecture Test
A developer needs one more field for an order confirmation. The inventory module already has it, so they import a convenient internal class. The code compiles. The feature works. The boundary on the architecture diagram has just disappeared. That is a practical problem worth solving before splitting an application into Read more