For all those who are interested, I am sharing my experience here
We were called at BPPIMT, Kolkata at 9 am. The interviews for System Engineer Specialists (SES) and Power Programmers (PP) were being done by different set of panelists. Candidates who couldn’t crack PP interview were given one more chance to sit for SES position. The interview for SES was very short (10-15 minutes) and they asked basic questions (as my friends told me).
So my turn came at around 7 in the evening.
Firstly, a written test of 30 minutes was held where we had to write a program on a piece of paper. The program was to find the next smallest palindrome of a given number. I used 2-pointer method to solve this. Writing on a paper is very different than writing the code in an IDE. I messed up with cuts and arrows and my code was very difficult to read. I thought of writing comments but that made the situation even worse 
After the test, my interview was taken which goes like this:
Panelist: Tell me about yourself
Me: Explained
P: Asked me the approach to solve a tree-dp problem (it involved bitmasking as well).
M: Answered
P: Asked me the approach to solve a graph coloring problem.
M:Answered
P: Given a number, keep adding the sum of its digits until you get a single digit.
I asked the constraints but he asked me to write the best code I could write
Since I couldn’t think of any other approach other than brute force, I wrote the brute
force method.
P: Asked me to optimize it.
I thought of digital roots and all, but couldn’t come to any solution that fast.
P:Okay, we will come back to this later. Explain me your projects.
M: Explained (I took more than 10 minutes in this)
P:Nice, you solved 3 out of 4 problems which were way tougher than the one you
couldn’t solve. If you won’t be able to optimize it, I will not be able to select you. At
least explain me the approach you will follow.
I was still not able to come up with anything so, I said I will generate answers for smaller test cases and look for a pattern.
P: Go on. Take your time.
I started with three digit numbers and found out that the answer was following the
pattern of N modulo 9, where N is the number. And for N modulo 9 to be zero, the
answer was 9. Example 123=1+2+3=6 and 123 modulo 9 =6
M: Explained this to him.
P(Impressed): Well done. Which language do you prefer?
M: C++
P: Will this algorithm work in C++ if the number of digits in the number is more than 10^5?
M: Yes, we will take the input as string and do the required modulo operation on the
string.
P: Asked me to write the code for the same.
M: Written.
P: Asked me some modulo properties and the reason why it follows so.
M: Explained.
P: How good are you with OS and SQL?
M: Not so good, but I’m okay.
P: Explain trigger in SQL with an example.
M: Explained
P: Explain Inverted paging
M: Explained
P: What is neural network?
M: I don’t know 
P: Thank you for not answering this. We’re done. Any questions?
M: No sir.
P: You can go to the HR now.
It was more like live coding rather than an interview.
The HR round was not any round, they were just verifying all the documents. When I left the place at around 10 pm, there well still some candidates waiting for their HR round xD
