I was asked to design a database based on the requirements given by the interviewer and had to write some queries too. I was asked an object oriented design problem too. Details about Performance Testing. Explain dynamic, divide & conquer way of programming. Implement fibonacci using iterative, recursive and dynamic programming. Explain merge sort. How it uses divide & conquer programming. Circular linked list implementation based on a problem given. Differences between linked list and array list. Differences between C++, Java and Python. (I didn't revise C++ much, so couldn't answer virtual functions in detail) Difference between Future and Callable. Explain Executor Services.

what is lock, reentrantlock, synchronized, how to make threads run in sequence, wildcards, eg. of wildcards, bus ticketing design system, what is diff between treemap, hashmap, concurrenthashmap, how to handle service which has used up full memory, lifecycle of bean, transactional annotation and its attributes, what is microservice, how 2 or more service behaves in case of failure of any one of the service, how to handle it, long to short url design