Java 8 features, Streams, Collectors.groupingBy, Exception handelling in java & SB, primtive vs wrapper,
exception Handelling and method overriding rules, how to catch checked and uncheked exception using multiple catch blocks, SB annotations, how to create REST APIs in SB, Bean Scopes, IOC containers, Application context, Microservice Componnents, Feign vs Kafka, SAGA Pattern