Nference Interview Experience for SDE

Round-1

The first round was an online coding test. This test consists of 2 coding questions and 1 hour to solve them and platform of test was Hackerrank.

Problem -1

First problem was very interesting and also standard. How many binary search tree(BST) are possible with given number of keys.

Solution: This can be done by two method. One way is a DP solution https://www.geeksforgeeks.org/number-of-unique-bst-with-a-given-key-dynamic-programming/

Another way to solve this problem is very easy and answer is just catalyn number. You can refer to https://www.geeksforgeeks.org/total-number-of-possible-binary-search-trees-with-n-keys/

Problem -2

Second problem was easy and just the implementation of BFS in a grid. It was something like. Check if there exist a path from cell(0,0) to cell(n,m) in a grid with n rows and m columns in which some cells are blocked.

Around 400 students gave the online test and around 15 -20 got selected for further on-campus interview rounds.

Tip :- It’s better to know more than one approaches of a problem. 

Round -2 (Technical Interview Round-1)

The interviewer jumped right on asking me some easy coding problems.

1) How will you check if a given binary tree is a BST or not.

https://www.geeksforgeeks.org/a-program-to-check-if-a-binary-tree-is-bst-or-not/

2) Because this is a ML/AI based company and in ML/AI we have to deal a lot with matrices. So he asked me some simple matrices related problems like, Write code for multiplying two matrices etc.

Tip :- Practice a little bit to write code on paper.

Round -3(Technical Interview Round-2)

The second interview was already a little impressed with my online test results and first asked me how did you solve both problems so quickly(17-18 mins). Then he began with the problems .

1) First problem was based on using maps .Given two arrays A and B and we need  to print all the elements of array A which are not in array B.

2) I don’t remember the exact problem but it was something with trees and i was not able to write code for that. But i told him an approach for that problem and he was okay with that.

Then he asked me some puzzles and i more or less solved them and overall he was happy with my solutions.

In the end he asked me Why Nference?

Tip :- If you do not know the exact solution then discuss an approach that comes to your mind the interviewer will help you out.  

Round -4(HR Round)

The interview began with some compliments like, I have heard nice feedback about you from other interviewers that you are sharp. That boosted my confidence and made me a bit relax.

Now i was expecting some standard questions but he began with something completely different question.

What is the problem that you can think of around you?

At this very moment i realized it is going to be something like case study and i had no practice with case studies so got bit uncomfortable but then i took a deep breathe and gathered myself and we discussed about some problems and used my solutions like population, poverty etc.

Tip:- Be confident and relax.

Overall experience was very good. All the interviewers were very nice and helping.