ServiceNow Interview Experience for Associate Software Engineer (On-Campus)

Round 1(Online Coding Round – Hackerrank Platform): This round consisted of 1 Coding question and 15 Multiple choice questions. This round lasted for 60 minutes. One cannot switch between tabs during the test. Also, Webcam snapshots will be taken periodically.

The Coding Question:

Count distinct pairs with given sum:

Given an array arr[] of size N and an integer K, the task is to find the count of distinct pairs in the array whose sum is equal to K.

Input: arr[] = { 5, 6, 5, 7, 7, 8 }, K = 13 
Output: 2 
Explanation:
Pairs with sum K( = 13) are { (arr[0], arr[5]), (arr[1], arr[3]), (arr[1], arr[4]) }, i.e. {(5, 8), (6, 7), (6, 7)}. 
Therefore, distinct pairs with sum K( = 13) are { (arr[0], arr[5]), (arr[1], arr[3]) }. 
Therefore, the required output is 2.

Round 2(Technical Interview 1 – 60 Mins):

• Tell me about yourself
• A link to Collab workspace was shared, where two or more people can write/see codes written by others.
• The following were the questions asked A Small Coding snippet was given, find and correct mistakes.

  unsigned int i = 0;
  for(i = 100; i >= 0; i--) {
      printf(“%d\n”, i);
  }
  

• Given a linked list where the elements are not sorted, the task is to remove duplicates Version 1: Without using Additional space (can compromise on Time Complexity) Version 2: Additional space can be used and can create a new list Version 3: Additional space can be used but do not create a new list
• Given a string of length N consisting of lower-case English alphabets, the task is to count the number of substrings in which the frequency of each character is exactly K. Version 1: Brute-force on all Substrings –  Version 2: Optimise a little bit –  Version 3: Super optimized approach –   where  is the number of distinct characters present in the string – viz., 26 I also showed her why my approach will work, by telling her that this was the problem I improved on Geeksforgeeks earlier
• Discussion about one of my projects – If I were to extend my project, what feature would I implement?
• The Interviewer asked me if I had any questions

I was able to solve all the problems with ease, the interviewer was quite impressed.

Round 3(Technical Interview 2 – 60 Mins):

• Tell me about yourself
• A link to Collab was shared, it contained all of my codes in the previous Technical Interview round.
• The following were the questions asked: Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. Return the answer in any order. A mapping of digits to letters (just like on the telephone buttons) is given below. Note that 1 does not map to any letters.

  Input: digits = "23"
  Output:
  ["ad","ae","af","bd","be","bf","cd","ce","cf"]
  

• Version 2: You are also provided with a list of words; your task is to find how many words will be present in the output generated above
• Follow up: Can you do it in  time, where N is the number  of words and M is the maximum of the length of words., given that the length of the string digits will not exceed 15
• Question 2: Lowest Common Ancestor of two nodes in a Tree Version 1: LCA of two nodes in Binary Search Tree (using the property of BST) Version 2: LCA of two nodes in Binary Tree (Using Recursion) Version 3: LCA of two nodes in N-ary Tree (Single Query) Version 4: LCA of two nodes in N-ary Tree (Multiple Queries) – Can be solved using Euler Tour + RMQ
• Discussion on 2 of my projects – the brief idea of why we did them, how we did them, the scope of the project etc.
• Do you have any questions?

I was able to solve all the problems and it was a very good experience. The Interviewer helped me when I was stuck solving Version – 1 of the Key-pad problem.

Round 4(HM Interview Round – 90 Minutes):

Basic HR Questions

• Did you ever feel uncomfortable?
• What do you do when you feel uncomfortable?
• How did you spend time during the pandemic?
• Did you take the Vaccine?
• What do you know about the Company?
• Tell me something about your college
• When did you enjoy the best in your college?
• Did you ever feel uncomfortable in college?
• What did you do then?
• How do you convince a class of 60 students to attend a session? (They’ll not listen to you, they already have 75% attendance, punishing will bring chaos – How will you convince them?)

Some Technical Stuff

• Tell me about your projects
• Talk about the Database Schemas used in your projects
• If you want to scale your project, what would you prefer, vertical scaling or horizontal scaling, or both?
• System Design-based questions – Functional requirements, UI design, database schemas, load balancing, etc.
• Do you have any questions?

Again, the interviewer was quite impressed, it was a very friendly and healthy conversation.

Some key takeaways:

• The Interviewer is always there to help you. Always ask questions/hints whenever you’re stuck. Make sure you understand the problem statement.
• Practice coding problems. Hackerrank, GeeksforGeeks, and Leetcode have a good collection of problems asked in Interviews.
• Do a good number of interesting Projects. Projects add great value to the Resume.
• Never talk about your weaknesses. Never give them a reason to reject you

Verdict: Selected for Associate Software Engineer Role