Codenation Interview Experience (On Campus for Internship)

CodeNation visited our Campus for Hiring Summer Interns. The process was as follows:

1) Online Coding Round
3 questions based on Data Structures and Algorithms, were asked in this round, to be solved in 75 minutes. The questions were of Medium to Hard difficulty level. The first problem was based on Disjoint Set Union (Could also be done using DFS), the 2nd question was a implementation based question and the third problem was a Dynamic Programming Problem. Those who solved 2 problems were shortlisted was for further interview Rounds
Note: Competitive Programming can be really helpful for this round as it gives an edge over others

2) Telephonic Interview
This round the interviewer mainly focused on the Previous Internships and Projects that I had mentioned in my Resume. One needs to be well versed about the Project. It was a 40-45 minutes interview where in-depth questions related to the Project were asked. There was a shortlisting after this round too.

3) Technical Interview – 1
This round mainly focused on Algorithms and Data Structures. I was asked 5 questions. The first question was that given an array N integers where every number appeared twice except one element, the task was to find the number occurring once. I suggested the O(N) approach with O(1) memory where we take the xor of all the array elements and in the end the value of xor is equal to the required number. The interviewer then modified the question a bit such that the numbers occurring twice had their occurrences consecutively for example arr = {1, 1, 2, 2, 3, 4, 4}. In this Case the answer would be 3. After some discussion with the interviewer I gave a Binary Search based Solution and wrote the code for it and the interviewer was satisfied with it. The next question was based on the dequeue. The third problem was to find the least greater element lying on the right side for each element of the array. Then a hashing based question was Asked followed by a simple Dynamic Programming Problem. The Interviewer was very friendly and the interview lasted for about 45 minutes. Also, it is suggested to read the question very carefully, discuss your approach with the interviewer constantly and not be in a hurry to code the logic 🙂

4) Technical Interview – 2
This round focused on Abstract Problem solving. I was asked to share my experience of doing something which was really challenging for me when I did it and later I could overcome it. I had a discussion about the same with the interviewer. Then he asked me to define Precision and Recall and then tell which one according to me was more important to have (I had mentioned A Machine Learning/ NLP related Internship in my resume thus was asked this). Then he asked me about a project where I mentioned about using a Python Library- Textblob and was asked about my decision to do the same followed by some technical questions related to it. After this, I was asked to think like a Data Scientist and assume that i was made available the Facebook Dataset(Sounds cool right :P) and come up with ideas of using the Data in a way which could be useful. Basically, I was supposed to look for ideas where the Data could be used in a productive way. I gave about 6-7 ideas of using it. I was constantly asked questions like How I would use the data more effectively for each and every use case I stated. The key here is to be confident about your ideas and constantly discuss it with the interviewer. In the end, he picked up one use case I had talked about before and was asked about the data structure and algorithm that I would Use to do the same. I explained him my approach and wrote the pseudo code for the same. After this the interview asked me if I had any questions for him.
This Interview lasted for about an hour and was pretty exhaustive but at the same time the interviewer was really friendly and discussed all the ideas pretty deeply which made it an interesting experience

In the end, I was told that I had been selected as a Summer Intern at CodeNation. It was a great experience interviewing for the same 🙂