IBM

Overall, the experience was good, and I felt quite comfortable during the process. IBM's test was actually easy compared to what I had expected, though I must admit that I was underprepared this time. I could still manage a decent number of questions

Core Java & OOP What are the four pillars of Object-Oriented Programming? Can you explain each with examples? Difference between an abstract class and an interface? When do you use which one? What is polymorphism? Explain compile-time vs run-time

I had three interview rounds. The first two rounds were technical, and the third round was HR. First round was completely on Core Java basics. The questions were around the collection framework and OOPs concepts.