Code Mill Hub | Backend Engineering https://code-mill-hub.com/blog/ Deep dives into Java, Spring Boot, and high-performance backend architecture. en-us shflzp12@gmail.com (Maria) shflzp12@gmail.com (Maria) Mon, 29 Jun 2026 00:00:00 GMT https://code-mill-hub.com/blog/spring-boot/2026-06-29-asynchronous-outbound-gateway-pattern-spring-boot-jpa-kafka/ Reliable External API Delivery with Spring Boot, PostgreSQL, and Kafka https://code-mill-hub.com/blog/spring-boot/2026-06-29-asynchronous-outbound-gateway-pattern-spring-boot-jpa-kafka/ Persist external-call intent with business data, claim work safely across replicas, classify retries, handle ambiguous HTTP outcomes, and use Kafka only through a durable outbox or CDC boundary. Mon, 29 Jun 2026 00:00:00 GMT shflzp12@gmail.com (Maria) External IntegrationSpring BootPostgreSQLTransactional OutboxApache KafkaIdempotency