Core Java Basic understanding of JVM , JDK ,JRE Basic understanding of Memory OOPS Concept Encapsulation Abstraction Polymorphism Inheritance String l String Builder & String Buffer Arrays Garbage Collection Exception Handling Method & Classes Constructor Serialization Collection Design Pattern Multi-threading Spring JDBC Hibernate Spring MVC Spring Boot Spring Security Spring Batch JavaScript Microservice REST API JPA Server JAVA 8 Features Junit Latest Java features of Java 9 ,10,11,12,13,14 Oracle SQL PL/SQL Agile methodology Git MAVEN Jenkins(CI/CD tools) Swagger SonarQube Tomcat Programs Basic Concept of Docker Basic Unix Command Basic Concept of AWS ElasticSearch RabbitMQ Spring Cloud Confluence Kafka ActiveMQ Kubernetes WSDL & SOAP JSON JMS JSP & Servlet Want to learn REST API Interview Questions , visit https://javainterview2020.wordpress.com/?p=7 .