Airtel interview experience Real time questions & tips from candidates to crack your interview
SDE - 1
Airtel
4 rounds | 6 Coding
problems
Selected Interview preparation journey
Journey
I have did my Engineering from National Institute of Technology, Kurukshetra and I have started my preparation from my 6th semester. I have done 350+ question on GFG and 400+ question on Leetcode.
Application story
The company visited my campus and above 7.5 CGPA students were selected to sit for the placements. It had 3 technical round followed by HR round.
Why selected/rejected for the role?
I was selected for this role because I have a good hold on DSA and the core CS fundamentals. One should have good knowledge of DSA to crack any good company. In both technical round I was able to answer all the question from brute force to optimise along with time and space complexity.
Preparation
Duration: 6 months
Topics: Object-Oriented Programming, Data Structures and Algorithms, Operating System, Database Management System, Computer Networks
Tip 1 : Questions are asked on DSA, so practice questions and it is not the number of questions you practice, but how well you practice the questions. Prepare a notebook and write down the approach you follow. Make proper notes and maintain that notebook. Will help for quick revision.
Tip 2 : Conceptual questions are asked from topics other than DSA. So watching videos on youtube will not help. Read the book thoroughly to make yourself ready for interviews.
Tip 3 : ALWAYS read about the real-life examples of the concepts you read. This is often asked in interviews and you will definitely regret failing to answer this question.
Application process
Where: Campus
Eligibility: Above 7.5 CGPA
Tip 1 : Having projects in resume will help you to give the direction to your interview, which increases the chances of selection.
Tip 2 : Add some achievements other than academics, it shows that you are a team player and increases the probability of getting shortlisted. BUT do not write anything that is not true or else, it will backfire.
Interview rounds
01
Round
Medium
Online Coding Interview
Duration90 minutes (60 minutes for coding and 30 minutes for MCQs)
Interview date25 Nov 2020
Coding problem2
The test was conducted in the evening from 7:00 pm to 8:30 pm. Because of the covid situation, the test was online and was given by all the students from their home.
Login window of 15 minutes was given and all students were supposed to login within initial 15 minutes (between 7:00 and 7:15 pm). The test was conducted on AMCAT and webcam was on during the whole test duration.
There were two sections in the test: 1.) Coding round with 2 coding questions - 60 minutes (2.) MCQ round with 30 MCQs - 30 minutes
120 students appeared for this round and 20 were shortlisted for further process.
1. Count Frequency
Easy
15m average time
85% success
0/40
Asked in companies
You are given a string 'S' of length 'N', you need to find the frequency of each of the characters from ‘a’ to ‘z’ in the given string.
Example :
Given 'S' : abcdg
Then output will be : 1 1 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2. Longest Common Prefix After Rotation
Moderate
30m average time
60% success
0/80
Asked in companies
You are given two strings 'A' and 'B' where string 'A' is fixed. But you can perform left shift operations on string B any number of times.
Your task is to find out the minimum number of left-shift operations required in order to obtain the longest common prefix of string 'A' and 'B'.
Note:
Left shift is defined as a single circular rotation on the string after which the first character becomes the last character and all other characters are shifted one index to the left.
For Example:
If A = “an”, B = “can”.
After performing one left shift operation, string B becomes “anc”.
After performing two left shift operations, string B becomes “nca”.
Follow Up:
Can you solve this in linear time and space complexity?
02
Round
Medium
Video Call
Duration50-60 minutes
Interview date3 Oct 2020
Coding problem2
This round started at 11 am and went till 3 pm.
Out of 120 students that appeared in online coding test, 20 were shortlisted for the first round of interviews.
In this round, everyone was asked some moderate level coding questions. We were supposed to write the code in our IDE, present the screen and show the interviewer the output of our code.
The interview started with the introduction being followed by 2 coding problems.
1. Longest subset zero sum
Easy
15m average time
85% success
0/40
Asked in companies
Ninja loves playing with numbers. So his friend gives him an array on his birthday. The array consists of positive and negative integers. Now Ninja is interested in finding the length of the longest subarray whose sum is zero.
Problem approach
I solved this problem using hashmaps because of their O(1) search operation. I applied 2 nested loops and then used the hashmap to search for the third element to make the sum zero. Time Complexity of this approach - O(n^2)
Another approach that uses sorting also took O(n^2) time.
The interviewer was happy by my answer.
2. Count Frequency
Easy
15m average time
85% success
0/40
Asked in companies
You have 3 meeting rooms and the clients give you the timing at which they will be requiring the meeting rooms (like 11:00 am to 2:30 pm). Tell if it is possible to align all the meetings. Print true or false.
Problem approach
This problem was based on CPU scheduling concept of Operating System.
For this problem, I created a variable and used it as a timer. This timer was updated as time=(time+0.5). I also created an array of bool type of size three which represents 3 meeting rooms.
After this normal iteration was done to check the availability of meeting rooms during the entire day.
When I told the interviewer that this problem is based on OS, he smiled and was very much impressed with my approach.
Time complexity of my approach - O(n)
03
Round
Medium
Video Call
Duration40 minutes
Interview date3 Oct 2020
Coding problem0
Out of 20 students, 11 were selected for this round. This round started at 3:30 pm, same day and went till 7:00 pm.
This round was also conducted virtually, on google meet. This round was based on internships and the project work.
Projects were discussed thoroughly. Questions asked were:
-- What was the approach you used in the beginning and tell about all the optimization you did on different levels of your project.
-- What real-life problem does your project solve?
-- What was the major learning from this project apart from the technical perspective?
-- Responsibilities as a Teaching Assistant.
04
Round
Medium
HR Round
Duration20 minutes
Interview date3 Oct 2020
Coding problem2
7 students were shortlisted for the HR round. This round started at 7:30 pm and went till 8:30 pm.
Like all the other rounds, this round too was virtual (on google meet). In the beginning, the interviewer introduced himself and then asked questions based on my resume.
All the 7 candidates were selected in the HR round.
1. Tell me about yourself.
Problem approach
Tip 1 : Share less about your family and more about your technical skills.
Tip 2 : Tell about the work experiences and the projects you did to assist the skills you mentioned.
Tip 3 : Always prepare this part before the interview and practice in front of the mirror.
2. Project And Previous Internship Questions
What type of projects you did at CDAC? What problem that project solved?
Since my project was based on chatbots, I was asked these questions:
-- What all chatbots have you used in real life? What are they used?
-- What is your opinion about the quality of service chatbots provide?
-- My (interviewer's) experience with chatbots not really good. What further changes can be done to improve the chatbots so that all the queries can be solved by them?
Problem approach
Tip 1 : These questions were based on my project. So having a thorough and detailed knowledge about the project is a necessity to ace such questions.
Tip 2 : Always research the problems that your project will resolve. This is the most repeated question of the interviews.
Here's your problem of the day 
Solving this problem will increase your chance to get selected in this company
Skill covered: Programming
Which is a DDL command in SQL?
Choose another skill to practice
Start a Discussion
Similar interview experiences
SDE - 1
3 rounds | 3 problems
Interviewed by Airtel
Selected 
1221 views
0 comments
0 upvotes
SDE - 1
4 rounds | 8 problems
Interviewed by Airtel
Rejected
1138 views
0 comments
0 upvotes
SDE - 1
3 rounds | 5 problems
Interviewed by Airtel
Selected 781 views
0 comments
0 upvotes
SDE - 1
3 rounds | 5 problems
Interviewed by Airtel
Selected 1174 views
0 comments
0 upvotes
Companies with similar interview experiences
SDE - 1
5 rounds | 12 problems
Interviewed by Amazon
Selected 104483 views
24 comments
0 upvotes
SDE - 1
4 rounds | 5 problems
Interviewed by Microsoft
Selected 49656 views
5 comments
0 upvotes
SDE - 1
3 rounds | 7 problems
Interviewed by Amazon
Selected 30954 views
6 comments
0 upvotes