Wipro Tech Lead interview questions

Implement LRU Cache / Producer-Consumer / Thread-Safe Singleton Find kth largest element / Merge intervals / Detect cycle in linked list Explain difference between HashMap, ConcurrentHashMap, and Hashtable How does Java Memory Model work (heap, stack, GC generations)? Explain equals() vs hashCode() and why both must be overridden What is immutability? How do you design an immutable class? When would you use CompletableFuture vs threads?