GC dump, heap dump, heap usages using real time cases, SQLs , how to sort using hashmap, performance tools like Jmeter, configuration of kafka , consumer groups, brokers, db isolation levels with real case scenarios, change data capture in db, JPA and its constructors, correlation id's in Kafka, kafka stream, SWS messaging services, reentrant lock, blocking queue,Java executor framework, concurrent packages, how GC changed over the java versions, types of singleton pattern, completable future, lombok libraries, difference between treehashmap and linkedhashmap