80 questions · from 8 interviews
Qualcomm interview questions
Every question candidates reported from their Qualcomm interviews, most frequently asked first. Each links to the write-up it came from, so you can see the round and how it went.
Qualcomm coding and DSA questions
- 01
Find Employees with 2nd Highest Salary per Department
Write a query to find the employees who have the second highest salary within each department, and discuss any follow‑up scenarios related to ranking or ties.
From Staff Software Engineer | Qualcomm | Interview Experience | Offer
- 02
Determine size of struct without builtin sizeof
Write a C function that computes the size of a given struct without using the sizeof operator. You are not allowed to assume any prior knowledge of the struct's fields or their types.
From Qualcomm Software Engineer Oncampus Interview Experience
- 03
Detect and remove cycle in a linked list
Given the head of a singly linked list, implement a function that detects whether the list contains a cycle. If a cycle is found, modify the list to remove the cycle so that it becomes a linear list.
From Qualcomm Software Engineer Oncampus Interview Experience
- 04
Remove duplicates from unsorted linked list without extra memory
Given the head of an unsorted singly linked list, write a function to delete all duplicate nodes without using hash tables, maps, or any additional data structures.
From Qualcomm Software Engineer Oncampus Interview Experience
- 05
Perfect Square Number Theory Problem
Find the number of positive integers n such that n(n + 84) is a perfect square.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 06
Circular Arrangement of Flags
There are 8 shops arranged in a circle. Place flags on exactly 3 shops such that no two selected shops are adjacent. Find the number of possible ways.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 07
Letter Coding
Given the coding PLANT = 42135 and BRIDE = 15423, find the corresponding code for CLOUD.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 08
Direction Sense Distance Problem
A person moves 10 m North → P, 5 m East → Q, 7 m South → R, 5 m West → S, 5 m South → T. Find the distance between T and Q.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 09
Time and Work – C Alone
A can complete a work in 24 days, B in 30 days. A works alone for 4 days, then A and B together for 6 days, then C joins them and all three finish the remaining work in 4 days. Find how many days C alone would take to complete the work.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 10
Number of OR Gates
Find the number of OR gates required to implement an expression similar to XY + YZ + X'Z.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 11
Number of AND Gates
Determine the number of AND gates required to implement an expression similar to AX(B + 1 + R).
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 12
Decimal to Binary Conversion
Convert the decimal number 307 into binary.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 13
Multiple‑Level Pointer Output
Given a code snippet with multiple pointer levels (e.g., int x = 5; int p = &x; int q = ...; p = p + 8;), determine the output of expressions such as x, p, and q.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 14
Pointer with Array Output
For the code int arr[] = {3, 6, 9, 12, 15}; int p = arr; p = p + 2; determine the results of p++, p, and (++p) and explain the difference between p++, (p)++, and (++p).
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 15
Loop with Continue Output
Given the loop for(int i = 1; i < 5; i++) { if(i == 3) continue; cout << i; }, determine the output or how many times the print statement executes.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 16
XOR and Left Shift Output
For the code int a = 26; int b = 11; a = a ^ (1 << 2); followed by additional operations, find the final values of the variables.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 17
Multiple XOR Operations Output
Given int X = 12; X ^= X 2; find the final value of X.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 18
Bitwise Expression n &(n‑1) Output
Trace the code containing if ((n & (n - 1)) == n) and if(n == 0) break; and determine the final output values.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 19
SJF Scheduling Average Waiting Time
Given processes P1 (arrival 0, burst 7), P2 (arrival 2, burst 4), P3 (arrival 4, burst 1), P4 (arrival 5, burst 4), calculate the average waiting time using Shortest Job First scheduling.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 20
BST Construction, Deletion, Preorder Traversal
Insert the elements 88, 66, 90, 50, 55, 53, 57 into a BST, delete 66, and provide the resulting preorder traversal.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 21
2D Array Address Calculation
For an array with index ranges A[-3...5, -5...8], each element occupying 2 bytes and given A[0][0] = 234, calculate the base address and the address of a specified element.
From Qualcomm OA Experience 2026 | 60 Questions | Aptitude + Technical + Course Specific | 90 Minutes
- 22
Spiral Traversal of Matrix
Given an N×M matrix, traverse and print its elements in spiral order.
Medium · From Qualcomm Associate Engineer Interview Experience [6 Month Exp.]
- 23
Detect Cycle in Linked List
Detect if a linked list contains a cycle. Explain the approach and provide a mathematical proof (Floyd’s Cycle Detection Algorithm).
Medium · From Qualcomm Associate Engineer Interview Experience [6 Month Exp.]
- 24
Reverse String using Recursion
Write code to reverse a string using recursion.
Hard · From Qualcomm Associate Engineer Interview Experience [6 Month Exp.]
- 25
Swap Nodes in Pairs (Linked List)
Given a linked list, swap every two adjacent nodes and return its head. I had to explain my approach and write the fully working code.
Hard · From Qualcomm Associate Engineer Interview Experience [6 Month Exp.]
14 more in the Qualcomm write-ups.
Qualcomm system design questions
- 01
Hospital Management System Schema Design
Design the database schema for a hospital management system, defining tables and relationships across entities such as patients, doctors, appointments, treatments, and billing.
From Staff Software Engineer | Qualcomm | Interview Experience | Offer
- 02
Report Generation Application Design
Design a report generation application where a user provides report parameters. The system may call external APIs and look up data from a database containing millions of records, while handling scalability, performance, and reliability concerns.
From Staff Software Engineer | Qualcomm | Interview Experience | Offer
- 03
High‑Throughput Highly‑Available System Design
Design a high‑throughput, highly‑available system that operates across multiple clouds. Discuss failure handling, retry mechanisms, resiliency strategies, and how to achieve low latency under heavy load.
From Staff Software Engineer | Qualcomm | Interview Experience | Offer
- 04
RAG‑Based Prediction System for Python Code
Design a Retrieval‑Augmented Generation (RAG) based prediction system where input documents are Python code files. Explain how you would ingest the code, generate embeddings, retrieve relevant context, and produce predictions.
From Staff Software Engineer | Qualcomm | Interview Experience | Offer
- 05
Singleton Design Pattern
Explain the Singleton design pattern, how to ensure thread safety in its implementation, and write the corresponding code.
Medium · From Qualcomm Associate Engineer Interview Experience [6 Month Exp.]
- 06
Design Memory Leak Analyzer in C++
Design a Memory Leak Analyzer in C++, explaining the high-level object-oriented design and approach.
Medium · From Qualcomm Associate Engineer Interview Experience [6 Month Exp.]
- 07
Object-Oriented Design (Singleton Class)
I was asked to explain the Singleton class, how to ensure thread safety in its implementation, and to write the code for it.
- 08
Design a 5-star Rating React Component
Implemented a reusable and accessible rating component with interactive states and animations.
- 09
CRT Display Screen Tearing Algorithm Design
Consider a CRT display panel and an SoC chipset. Both share a single memory buffer: the SoC writes the next frame (producer), and the panel reads from it (consumer). Assume 120 FPS and a 1ms turnaround time (TAT). In CRT technology, the panel displays frames…
From Qualcomm | Senior Engineer | Hyderabad | April 2024 [Offer]
- 10
Design Text Editor with Undo/Redo
Design a text editor that supports up to 10 undo/redo operations. Initial Assumption: Users cannot edit previously written letters. Follow-Up Question: How would you modify the design to allow editing and deleting?
From Qualcomm | Senior Engineer | Hyderabad | April 2024 [Offer]
Qualcomm behavioural and HR questions
- 01
Behavioral Questions
Discuss my problem-solving approach, how I handle challenges in a team environment, and my expectations from the role.
From Qualcomm Associate Engineer Interview Experience [6 Month Exp.]
- 02
Resume and Project Discussion
I was asked to explain the projects I had worked on at my previous organization, the role I played, and how I contributed to runtime improvements through my code changes.
- 03
Behavioral: Dealing with Strict Managers and Deadlines
How do you deal with a strict manager? How do you handle strict deadlines and unclear instructions?
Qualcomm other questions
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CPU‑Memory Frequency Stall Scenario
Suppose the CPU supports 1.5, 2, 2.5, and 3 GHz while currently running at 3 GHz. The memory supports 2, 2.5, and 3 GHz but is currently running at 2.5 GHz. Will there be stalls? How would you resolve this?
From Qualcomm | Engineer
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- 14
Core Architecture Explanation
What is a Core at the architecture level? Explain how it works.
From Qualcomm | Engineer
- 15
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Branch Prediction and Reinforcement Learning
How is Branch Prediction related to Reinforcement Learning?
From Qualcomm | Engineer
- 17
Unified vs Separate Memory Architectures
Unified Memory vs Separate Memory architectures. Why are they designed differently?
From Qualcomm | Engineer
- 18
- 19
Device Drivers Overview
Device Drivers: What are they? Why are they needed? Basic understanding of driver architecture.
From Qualcomm | Engineer
- 20
Operating System Concepts
Explain defragmentation, thrashing, memory management, and virtual memory in detail, including follow-up questions.
Hard · From Qualcomm Associate Engineer Interview Experience [6 Month Exp.]
- 21
C++ Fundamentals
Discuss C++ concepts including: auto storage class, pointers and const pointers, memory layout, heap vs stack memory, virtual functions (with example and real-world use), lambda functions, function pointers (with code), and the volatile keyword.
Hard · From Qualcomm Associate Engineer Interview Experience [6 Month Exp.]
- 22
Process Scheduling Algorithms
Discuss process scheduling, including the best scheduling algorithm and Multi-Level Feedback Queue (MLFQ).
Hard · From Qualcomm Associate Engineer Interview Experience [6 Month Exp.]
- 23
Concurrency and Synchronization Primitives
Discuss mutexes, semaphores, and spinlocks, covering their differences, internal workings, and scenarios where spinlocks are preferred.
Hard · From Qualcomm Associate Engineer Interview Experience [6 Month Exp.]
- 24
Operating System Concepts (Defragmentation, Thrashing, Memory Management, Virtual Memory)
I was asked to explain topics like defragmentation, thrashing, and other memory management concepts; there were questions from virtual memory as well. The interviewer deep-dived into each concept.
- 25
C++ Concepts (auto storage class, virtual functions)
In C++, I was asked about the auto storage class, and to explain virtual functions with an example and describe their use case.
3 more in the Qualcomm write-ups.
Qualcomm interview questions FAQ
What questions are asked in Qualcomm interviews?
Candidates reported 80 distinct questions across 8 Qualcomm interviews. 39 coding and DSA questions, 10 system design questions, 3 behavioural and HR questions, 28 other questions.
How difficult are Qualcomm interview questions?
Of the questions candidates rated, 6% were easy, 44% medium and 50% hard.