Spring Data AOT Repositories: Better Performance AND Developer Experience

Spring Data AOT repositories are a new feature in Spring Boot 4 / Spring Framework 7 that moves repository implementation generation from runtime to build time. This delivers 50–70% faster startup, reduced memory usage, and better developer experience. By adding a Maven plugin execution for the AOT phase, Spring generates concrete repository implementation classes at compile time instead of dynamically at runtime. This makes debugging easier (visible generated SQL, gutter icons in IntelliJ 2025.3 to jump to implementations), catches query typos at build time rather than in production, and is especially impactful for large applications with many repositories. The feature also serves as a stepping stone toward GraalVM native images.