1. Mostly spring mvc, java, and questions from the technology you have worked on 2. Multithreading on hashmap. What could be the issue of using hashmap in a multithreaded environment? 3. Find longest unique subsequence in the given string 4. Find/Count unique elements in an integer array 5. count number of islands in a given binary matrix. 1 represents island and 0 as water. geeksforgeeks has this questions. Moving diagonally is not allowed 6. Design twitter timeline(feeds). database design, how you will handle caching. Discussed CAP theorem. Discussed Caching strategies. 7. System design to read a file which has data and operation to be performed give a line by line. Ex a=5, next line b= 10, next line a*b. This design extended to support float, doubles, boolean, vector and complex numbers. Like if the file has a=5+i8, then how you handle such scenarios. How you will store and process data.