LTIMindtree Interview Experience for Software Engineer

After qualifying initial Aptitude and Coding round I got an invitation to the next round of Technical Interviews.
I joint the interview meeting initially interviewer ask me about myself, then he immediately asks me the following scenario:

Interviewer: Do you know about Data Structure?
Me: I said yes.
Interviewer: Okay and given a question based on Linked List.

I coded the question the Interviewer ask me about my logic and then start to ask me conceptual questions about Object Oriented Programming, Database Management Systems,s, and a little bit about Operating Systems.
Now it was gone approximately 1 hour.
In the end, he asks me to have him any questions then I ask him how can I improve myself. completed on my side, was and the interview over.
After one month I received a, qualifying email and invitation for HR round Interview.