NielsenIQ Interview Experience

Coding Round (150 minutes, 3 tasks): I got questions similar to these

1. https://www.geeksforgeeks.org/maximize-cost-of-deletions-to-obtain-string-having-no-pair-of-similar-adjacent-characters/
2. https://stackoverflow.com/questions/69005187/codility-stick-cut-challenge
3. return the length of the longest substring in which every letter occurs an even number

Out of 485 students, 30 were selected for the next round.

Tech Round – 1

1. Introduce yourself
2. Tell me about the internship and work that you are doing right now.

Let’s start with coding challenges. How good are you at DSA?

1. Tell me about Array. How does it work and what are the operations you can perform?
2. Tell me about Sorting Techniques and their time complexities.
3. Code any sorting algorithm and try to optimize it. Explain the code with output.
4. Why time complexities are important?
5. Tell me about the Linked list, its operations and its application.
6. How can we print the middle element it Linked list with one pass?
7. What are stack and queues and how can they be implemented and what are their applications.
8. What are the methods used in the operations of stacks and queues?
9. Code for printing the first non-repeating character in a string.
10. Code for reversing the string with recursion.

Let’s start with Java and SQL. How good are you at Java and SQL?

1. What is OOP’s concept and what are its features?
2. How we can achieve data abstraction in Java?
3. What is an interface, why it is used, what is their method?
4. How Java handles Exception?
5. What are errors and exceptions in java?
6. Why SQL is used?
7. Types of SQL commands for example.
8. Why Joins are used?
9. Give me the Syntax of Inner Join.

Let’s start with Core Concept.

1. How the internet works, explain layer by layer.
2. What is DNS, and how does it work.
3. What is Cache?
4. Tell me something about protocols for example.
5. What is HTTP, what are the methods used here?

Puzzles:  

1. You have a birthday cake and have to cut it into 8 equal pieces by making 3 cuts only. How do you do it?
2. You have 5 jars of pills. Each pill weighs 10 grams, except for contaminated pills contained in one jar, where each pill weighs 9 grams. Given a scale, how could you tell which jar had the contaminated pills in just one measurement?

Final Interview(Tech + HR)

1. Introduce yourself.
2. Tell me about the minor project that you did in your semester.

Following that, all questions were around project and ML models.

1. How Linear regression works?
2. How can you calculate the error in it?
3. Why is RMSE but not normal error formula?
4. What is the main intuition behind SVM? Why do we have to add a third axis in some cases and how can we convert it?
5. What is the decision boundary in a decision tree?
6. Which is a better decision tree or random forest?
7. What is NoSQL DB used?
8. If you have a database of all the students in your university from start to today, how would you search your name or how would I get all the students in your class.

Following this the interview transformed into a behavioral and then managerial round.

1. What is your hobby?
2. What sports do you like? Who is your favorite sportsperson?
3. Tell me about a situation where you had to make a difficult decision.
4. What is your procedure for approaching any work?
5. Imagine your group is getting a project, and I’m aware of all the skills that your group has, and you got a work which you don’t know, how would you handle the situation? You won’t have the facility to swap the work with someone else.
6. Imagine you are loaded with work and the deadline is the next day, how would you submit all the work?
7. Imagine you are the team leader and your friend had deleted an important and latest version of the code file from the system, but you have the prior version. If you submit the prior version code, no one will doubt but if they check thoroughly, they may suspect something. How would you handle the situation?
8. What do you prefer, a job or higher studies?
9. Why don’t you want to go for higher education?
10. Do you have any offers at hand? If you have then why you have applied for this company.
11. What are your future plans?
12. Why should I hire you not others?
13. Who is your role model and why is it so? Please be realistic.

That’s all I remember. I tried to write all the questions which were asked.

Later I was told that I am not selected after the HR round and I still don’t know where I went wrong in the interview as according to me both of these went perfectly well.

Hope this helps.