A head-to-head benchmark of the same Spring Boot app built for the JVM and as a GraalVM native binary - on real AWS hardware with a real database, run multiple times. Native wins startup, memory, and predictability; the warm JVM wins the median, peak throughput, and often the tail too - but the JVM swings run-to-run while native stays flat.
The javax to jakarta package rename is the hard part of the Spring Boot 3 upgrade. Why the one-line sed trick quietly breaks javax.sql and javax.crypto, which packages actually move, and how OpenRewrite does the whole migration for you. Tested on real apps.
Inject every bean that implements an interface into one field: a List or array ordered with @Order, a Set, or a Map keyed by bean name. With code.
Constructor injection in Spring Boot with Lombok @RequiredArgsConstructor: drop @Autowired, keep fields final, no boilerplate. Setup with Maven and Gradle.
