Completable Future Articles | Spring Boot 123

How to Implement Asynchronous Processing in Spring Boot - Using @Async and @EnableAsync

An implementation guide for @Async / @EnableAsync, compatible with Virtual Threads in Spring Boot 3.2+ / Java 21. Learn how to speed up your API by running email sending and external API calls in the background, with production know-how covering ThreadPoolTaskExecutor sizing, RejectedExecutionHandler, graceful shutdown, MDC propagation (TaskDecorator), and CompletableFuture, all explained with implementation examples.

2026-02-01