I recently appeared for the MTech CSE (Research) interview at IIIT Delhi and wanted to share my experience.
There were two professors on the panel.
The interview started with a basic introduction. After that, the first professor asked me about the longest piece of code I had written during my BTech. I talked about my major project, and we had a discussion on it for around 4-5 minutes. The discussion went somewhat deep into the implementation and concepts. I was able to answer most of it, but I did stumble towards the end on a follow-up question.
Then the second professor took over and asked whether I had prepared specific subjects for the interview. I replied that I was comfortable with all core subjects. He then asked if he could ask a question from Discrete Mathematics, and I agreed.
Question asked:
Suppose you are given a set of size n. What is the number of subsets with even cardinality?
I answered: $$2^{n-1}$$
He then asked why.
I said that since the total number of subsets is $$2^n$$ , intuitively half of them should have even cardinality and half should have odd cardinality.
He then pushed further:
“Why exactly half?”
At that point, I paused. I hadn’t studied a formal proof for this before. He clarified that they didn’t expect a memorized proof but wanted to see my thought process and reasoning ability.
I tried to think along those lines but couldn’t arrive at a convincing explanation. He then asked if I was familiar with combinatorial bijection arguments. I said I wasn’t, and we moved on.
Overall Experience
The professors were very polite and created a comfortable environment throughout the interview. It felt more like a discussion than a grilling session.
However, I personally felt the interview was quite short and could have included more questions to better evaluate my knowledge.
Takeaways
- Be prepared not just with answers, but also “why” and “how” behind them
- Interviewers may test your thinking process, not just memorized concepts
- Even if you don’t know a formal proof, try to build intuition on the spot
