Dimitri's tutorials about software development with Java and JavaScripthttps://dimitri.codes/https://dimitri.codes/introduction-contract-testing/https://dimitri.codes/introduction-contract-testing/Library upgrades can silently break your API contracts. Here's how to catch that with OpenAPI-Diff, Spring Cloud Contract, and Pact.Mon, 15 Jun 2026 00:00:00 GMThttps://dimitri.codes/dangers-ai-skills/https://dimitri.codes/dangers-ai-skills/In this post, I'll explore how AI skills can expose your agent to prompt injection, why seemingly safe skills still carry risks, and how to stay protected.Sat, 06 Jun 2026 00:00:00 GMThttps://dimitri.codes/authorization-server/https://dimitri.codes/authorization-server/Spring Authorization Server joining Spring Security 7 is the perfect moment to finally try it out. We'll look at configuring clients, testing OAuth flows, and customizing JWT token claims.Wed, 24 Dec 2025 00:00:00 GMThttps://dimitri.codes/opentelemetry-starter/https://dimitri.codes/opentelemetry-starter/Spring Boot introduced its own starter for OpenTelemetry in Spring Boot v4.0.0. This makes it easier to send logs, metrics and traces to any OpenTelemetry-backend. In this blogpost, we'll explore how to use this new starter.Tue, 23 Dec 2025 00:00:00 GMThttps://dimitri.codes/spring-retry-core/https://dimitri.codes/spring-retry-core/Spring Retry is no more... or at least not as a separate library. Instead of that, you can now utilize retry-related functionality within Spring Core! Which functionality? That's what this blogpost is all about.Mon, 22 Dec 2025 00:00:00 GMThttps://dimitri.codes/jsonmapper/https://dimitri.codes/jsonmapper/Spring Boot 4 includes an upgrade to Jackson 3. In this blogpost I'll talk about some of the big changes in Jackson 3.Sun, 21 Dec 2025 00:00:00 GMThttps://dimitri.codes/actuator-health-probes/https://dimitri.codes/actuator-health-probes/Spring Boot Actuator's liveness and readiness probes have been enabled by default since Spring Boot 4. What better time could there be to explore the possibilities of these probes?Sat, 20 Dec 2025 00:00:00 GMThttps://dimitri.codes/multi-factor-authentication-spring-security/https://dimitri.codes/multi-factor-authentication-spring-security/Spring Security 7 made it possible to easily set up Multi-Factor Authentication within your applications. This allows you to combine any of the authentication methods Spring provides and create an even more secure setup.Fri, 19 Dec 2025 00:00:00 GMThttps://dimitri.codes/dynamic-bean-registration-spring/https://dimitri.codes/dynamic-bean-registration-spring/Spring has a new way of registering beans programmatically called the BeanRegistrar. In this tutorial I'll talk about how and when to use it.Thu, 18 Dec 2025 00:00:00 GMThttps://dimitri.codes/resttestclient/https://dimitri.codes/resttestclient/Spring Boot 4 introduces us to a new testing utility called RestTestClient. RestTestClient provides a uniform experience when testing your API's regardless of whether you want to write a unit test, integration test or end-to-end test.Wed, 17 Dec 2025 00:00:00 GMT