pen and paper aptitude containing few mcqs and 3 programs ,missing element of an array, preorder traversal,and version comparison(versions given in strings) 2 technical rounds and 1 CEO round 1. explain about string immutability with example and memory representation after that some scenarios related to immutability 2. What is Abstraction and Encapsulation and their difference. --in the class,make a property read-only. 3. Write program explaining difference between overloading and overriding? after that the interviewed made some changes in the code indirectly asking following concepts. ---can we overload private methods? ---can we override data members? 4. Program for array rotation 5. Create custom arraylist 'add(index,data)' method using another data structure 6. Static keyword 7. Program related to collection: find no of occurrences of each character of a string 8. Program to Convert a Binary Tree into its Mirror Tree 9. SQL joins, projects in the resume. I answered almost everything correctly except for the 8th(was halfway there) .I was confident that I would clear this round,in the end I was informed by HR i didn't qualify first round, some of my friends who had different interviewers were asked very basics and cleared first round, So bring your fortune with you.