Build robust backend applications with Spring Boot. REST APIs, security, data access.
Spring Boot 4.0 and Spring Framework 7.0 landed together in November 2025 — the first major Spring release in three years. Null-safety via JSpecify, built-in API versioning, a modularized codebase, Jackson 3, and HTTP interface clients. Here is what matters for a production Spring shop, and what upgrading actually costs.