Perfios Interview Experience | On-Campus 2021
Perfios had recently come to our college to recruit full-time employees for the role of Member of Technical Staff(Software Development Engineer). The interview process was virtual.
Round 1: First we had an online test on Hackerearth, which involved 20 Aptitude questions and 3 coding questions.
Round 2 (Technical): Those who cleared the online test were interviewed in the first Technical Round.
First, we had a discussion on my projects. Then the interviewer asked about the time complexities of few Data Structures (Mostly Trees)
Then I was asked 3 coding questions on the array, linked list, and tree. The questions are as follows:
- Sort an array of 0’s and 1’s in O(n) time complexity and no extra space to be used.
- Reverse Linked List
- Print Level Order Traversal of given Binary Tree.
Then I was asked a few questions on OS, CN, DBMS.
- Process vs Threads
- TCP vs UDP
- Design a database (the tables’ names were provided by the interviewer) and then asked me to write queries on the database I designed.
This round went on for 50min
Round 3 (Technical): This round was technical as well. Since I already gave one technical round where all basic concepts were asked, this round was short and was for only 30min.
Here again, we had a discussion on my projects, few questions on OOPs, Java, DBMS.
- Difference between Array List and Linked List in Java. Which one will you prefer in which cases? Why will you prefer it?
- I was given 3 classes Car, Engine, and Maruti. I was asked to find out any OOPS related concepts/ relationships I can find from these classes.
- Abstract vs Interface and which will you use in which all cases and why?
- Time Complexities of searching sorting algorithms.
- Explanation of anyone Sorting Algorithm
- In DBMS I was again given 2 tables employee and department and was asked to write MYSQL queries based on the requirement.
Round 4 (Managerial): This round was for only 15min. We had a basic casual talk about the company, my favourite subjects, what I am interested in, my family background, etc..