This Week in Spring – December 23rd, 2025

The Spring ecosystem continues to thrive with numerous releases and community contributions. Recent developments include the Spring Boot 4.0 release, with subsequent updates and patches. A Bootiful Podcast features an interview with Spring co-founder Juergen Hoeller. Spring Boot 4 now offers improved Kotlin support and Spring Shell 4.0.0-RC1 is out. Several versions of Spring Modulith have been released. Spring Tools 5 has been updated, and Spring AI enhances LLM tool-call reasoning. There are also new releases of Spring Boot, Spring Batch, Spring Authorization Server, and Spring Cloud. Numerous articles provide guidance on breaking changes in Spring Boot 4, event-driven microservices, date values, JVM performance, platform building, API versioning, and gRPC support. The community contributes with starters, such as one for simplifying SSE implementation.