EJB
Enterprise JavaBeans (EJB) is a server-side component architecture for building scalable, transactional, and secure enterprise applications in Java. It provides a framework for developing distributed business logic, handling persistence, messaging, and concurrency, typically deployed on Java EE (now Jakarta EE) application servers. EJB simplifies enterprise development by abstracting low-level infrastructure concerns like transaction management and security.
Developers should learn EJB when building large-scale, mission-critical enterprise applications that require robust transaction management, security, and scalability, such as banking systems, e-commerce platforms, or enterprise resource planning (ERP) software. It is particularly useful in legacy or corporate environments that rely on Java EE/Jakarta EE stacks, where EJB integrates seamlessly with other Java technologies like JPA and JMS for comprehensive backend solutions.