1. What are the issue might appear in multithreading? 2. Concurrent Hashmap how it works? why is better than synchronised block? 3. how to achieve locking? difference between lock and shynchronised 4. Design patterns related questions ( example of various design pattern) 5. how to secure micro services in Spring? 6. how to optimise a query if you find out its slow? 7. difference between arraylist and linkedlist, which one is better? 8. Gave me a scenario and asked me how to solve this? 9. Different Joins in SQL. 10. Future, callable, executor service. 11. S.O.L.I.D principle with examples.
