Qualcomm Interview Experience for SDE (Off-Campus) 2023

I got a call from Qualcomm Chennai for a Software Engineer position. I am from CS background and had 1.5 years of experience. There are 4 Technical Rounds.

Round 1:

• Discussion about my last company, what they do and what is my role.
• Write a C program to get the size of variable without using sizeof() function.(https://www.cprogramming.com/tips/tip/finding-size-of-variable-without-using-sizeof)
• How to divide a number with 4 without using division operator?(Solved using Bit Manipulation)
• What are the different types of Linked Lists?
• Create a Linked List and insert a Node at given position.
• The interviewer asked a few Puzzles.

Round 2:

• Interviewer asked about my academic projects. Explained all the projects in detail.
• Write a program to Reverse a String.(https://leetcode.com/problems/reverse-string/)
• Write a program to Reverse a Linked List.(https://www.geeksforgeeks.org/reverse-a-linked-list/)
• Write a program to Reverse a Doubly Linked List. (https://www.geeksforgeeks.org/reverse-a-doubly-linked-list/)
• Asked a few puzzles.
• What is process? What is Thread? Difference between Process and Thread?
• What are Software Interrupts? Explain different types of interrupts?
• Implement MERGE SORT. Explained him the approach and coded the same.(https://www.geeksforgeeks.org/merge-sort/)

I was shortlisted in the 2nd round and called for an on-site interview.

Round 3(Managerial Round):\

• Asked a few behavioral Questions, What is your greatest Achievements? Questions on my projects.
• Asked to define a data structure for storing 12 bits of data.(Explained him with the help of structures).
• Questions from OS. 
  • What is process?
  • What is context switching? 
  • What are different types of scheduling algorithms?
  • Working of Round Robin Algorithm.
  • How Process is created?
  • What is process table? What is PCB(Process Control Block)? What are different types of attributes in PCB?
  • How does OS perform context switching?
  • What happens when we press a keyboard key? Explained him the steps involved in hardware level, OS level, and CPU level.
  • What is system call?
  • What is User space and kernal space?
  • Explain the memory layout of process.
• Insert a Node at given position in a Linked List?(https://www.geeksforgeeks.org/insert-a-node-at-a-specific-position-in-a-linked-list/)
• Count the number of set bits in a given number.(https://www.geeksforgeeks.org/count-set-bits-in-an-integer/)
• Given a puzzle and asked to write program in C.

Round 4:

• Asked about my projects.
• Given an input string s, reverse the order of the words.A word is defined as a sequence of non-space characters. The words in s will be separated by at least one space.Return a string of the words in reverse order concatenated by a single space (https://leetcode.com/problems/reverse-words-in-a-string/)
• Given the arrival and departure times of all trains that reach a railway station, the task is to find the minimum number of platforms required for the railway station so that no train waits. We are given two arrays that represent the arrival and departure times of trains that stop. (https://www.geeksforgeeks.org/minimum-number-platforms-required-railwaybus-station/)
• What is mutex? What is spin lock? what is Critical Section? 
• Given 2 resources and 4 threads. One thread locked the CS. How does other threads acquire the CS?
• What are System Calls? Different types of system calls?

Verdict: Selected