1st Round : He asked almost every concept from java spring and coding 1 . internal implementation of HashMap 2 . Implementation of LRU cache 3 . what is inversion of control 4 . What is Transactional annotation , he defined two defined method1 and method2 and written @transactional annotation on method2 and written 4 queries inside method2 and if exception occurred at execution of query2 then in this case query 1 will rollback or not 5 . what is IOC container ? 6 . A database query based on group by 7 . How to find latecy in API 8 . Types of Microservices