Qualcomm Interview Preparation and Recruitment Process

About Qualcomm

Qualcomm is a leading American multinational corporation known for its innovations in wireless technology, particularly in mobile communications. Here's a concise overview:

Qualcomm Interview Questions

Overview

Founded: July 1985
Founders: Irwin Jacobs, Andrew Viterbi, and others
Headquarters: San Diego, California, USA
CEO (as of 2024): Cristiano Amon

Core Business

Qualcomm specializes in:

Semiconductors for mobile devices
Wireless technology standards (like 3G, 4G LTE, 5G)
Mobile chipsets and platforms
Licensing of telecommunications patents

Major Products & Technologies

Snapdragon SoCs:
Qualcomm's flagship mobile processors, used in Android smartphones, tablets, laptops, and wearables. Snapdragon integrates CPU, GPU, modem, and AI engines.
Modems:
Industry-leading 4G and 5G modems (e.g., X55, X60, X70), used not only in Android devices but also in iPhones (until Apple transitions to its own modems).
RF Front-End (RFFE):
Hardware that works with modems for signal transmission—crucial for 5G.
AI & Automotive:
Qualcomm is expanding into automotive chips (e.g., for infotainment and driver-assist systems) and edge AI.
IoT & XR (Extended Reality):
Chips for smart devices, wearables, and virtual/augmented reality.

Business Model

Qualcomm has two major divisions:

QCT (Qualcomm CDMA Technologies): Hardware and chip design.
QTL (Qualcomm Technology Licensing): Royalties from its vast wireless patent portfolio—one of the most profitable arms.

Recent Developments

Investing heavily in AI processing, automotive platforms, and custom ARM-based computing chips.
Working with Microsoft and other partners to build Windows on ARM using Snapdragon processors.
Competing with MediaTek, Apple (for custom silicon), Samsung, and emerging Chinese semiconductor firms.

Qualcomm Recruitment Process

Qualcomm's recruitment process is designed to evaluate both technical proficiency and cultural fit, especially for roles in engineering, software development, hardware design, and R&D. While the specifics may vary by role and region, here’s a general outline of Qualcomm’s typical recruitment process:

1. Application / Online Submission

Submit your resume through Qualcomm’s careers portal or via campus placements, LinkedIn, or employee referrals.
Tailor your resume to highlight relevant experience in embedded systems, wireless technologies, AI/ML, VLSI, etc., depending on the role.

2. Online Assessment (for technical roles)

This round typically involves:

Coding Questions: Data structures, algorithms (on platforms like HackerRank).
MCQs: Topics may include:
- Operating Systems
- Computer Networks
- Digital Electronics / VLSI
- C/C++/Python
- Aptitude (in some cases)

Note: For hardware roles, expect questions on Verilog/VHDL, digital logic, or circuit analysis.

3. Technical Interviews (1–3 Rounds)

Conducted virtually or onsite. Focus areas depend on the role:

For Software Engineers:
- Data structures, algorithms
- System design (for experienced roles)
- Operating systems, C/C++, Python
- Real-time/embedded systems
For Hardware/VLSI Engineers:
- Digital logic design, CMOS, RTL design
- Verilog/VHDL, synthesis, STA (Static Timing Analysis)
- ASIC/FPGA flow understanding
Behavioral/Soft Skills Questions may also be mixed in.

4. Managerial or Team Fit Round

Evaluates:
- Communication and collaboration
- Problem-solving in real-life team settings
- Attitude, ownership, and adaptability
May include scenario-based questions and past project discussions.

5. HR Interview / Offer

Discussion of:
- Salary expectations and benefits
- Relocation, joining date
- Career goals and organizational culture
If selected, you receive a formal offer letter with compensation details.

Tips for Preparation

Brush up on DSA, core CS subjects, and role-specific skills.
Practice coding on platforms like LeetCode, HackerRank.
Review past projects—be ready to explain your contributions and design decisions.
For VLSI/hardware roles, refer to Morris Mano, Rabaey, and standard VLSI interview guides.

Qualcomm Interview Questions :

1 .

What are the advantages of having a multi-core processor?

Multi-core processors provide faster and more efficient computing.

* Improved performance and speed

* Ability to handle multiple tasks simultaneously

* Reduced power consumption

* Better multitasking capabilities

* Enhanced user experience

* Examples: Intel Core i7, AMD Ryzen 9

2 .

What is the difference between a task, a process, and a thread?

Task is a unit of work, process is an instance of a program, and thread is a subset of a process.

* Task is a single unit of work that needs to be completed.

* Process is an instance of a program that is being executed.

* Thread is a subset of a process that can run concurrently with other threads.

* A process can have multiple threads, but a thread can only belong to one process.

* Threads share the same memory space, while processes have their own memory space.

* Threads are lightweight compared to processes, as they require less overhead.

* Examples: A process can be a web browser, while a thread within that process can be responsible for rendering images.

* Another example: A task can be sending an email, which can be part of a larger process of composing and sending an email.

* Yet another example: A process can be a game, while threads within that process can handle graphics, audio, and user input.

3 .

Differentiate between a process and a thread.

A process is an instance of a program while a thread is a subset of a process.

* A process has its own memory space while threads share memory space

* Processes are heavyweight while threads are lightweight

* Processes communicate through inter-process communication while threads communicate through shared memory

* Examples of processes include web browsers, text editors, etc. while examples of threads include GUI updates, background tasks, etc.

4 .

How do you implement the overlap-add method of convolution?

Overlap-add method of convolution is implemented by dividing the input signal into overlapping segments and convolving each segment with a filter.

* Divide the input signal into overlapping segments

* Apply the filter to each segment

* Add the convolved segments together to get the output signal

* The length of each segment should be greater than or equal to the length of the filter

* The overlap between adjacent segments should be greater than or equal to the length of the filter minus one.

5 .

How much do you know about Qualcomm?

Qualcomm is a semiconductor and telecommunications equipment company based in San Diego, California.

* Qualcomm is a leading provider of wireless technology and services.

* They are known for their Snapdragon processors used in smartphones and other devices.

* Qualcomm has been involved in several legal disputes with Apple and other companies over patent infringement.

* They also have a strong presence in the development of 5G technology.

* Qualcomm has a diverse portfolio of products and services, including IoT solutions and automotive technologies.

6 .

Explain the difference between Moore and Mealy state models.

Moore state model outputs depend only on the current state, while Mealy state model outputs depend on both current state and inputs.

* Moore model: output is a function of current state only

* Mealy model: output is a function of current state and inputs

* Moore model has a separate output function, while Mealy model combines output and state transition functions

* Example: vending machine can be modeled using Mealy model as output depends on both current state and input (money inserted)

* Example: traffic light can be modeled using Moore model as output depends only on current state (red, yellow, green)

7 .

What is a Race Condition?

A Race condition is an issue that mainly occurs in multithreaded applications. It occurs when two or more processes or threads attempt to access a single shared resource. It also appears when the codes of a program are being processed in the wrong order.

Race conditions create deadlock problems while executing programs. Not only that, it makes errors while reading or writing data. Know that there are two types of race conditions: critical and non-critical.

8 .

Describe the ACID Properties of Databases.

ACID refers to Atomicity, Isolation, Consistency, and Durability.

Atomicity is the property that ensures whether a transaction is entirely executed or not. It ensures that a transaction is completed as a single unit – not in parts.

Consistency is the property that ensures data integrity in databases. If we change data in a database, it must be reflected in all the associated places. Simply put, there shouldn’t be any mismatches or errors among database data.

Isolation is the property that ensures all transactions must be performed without interruptions.

Durability is the property that ensures data is kept in databases for a long duration securely. There shouldn't be any data loss because of system malfunctions, crashes, etc.

9 .

Explain Mutex.

Mutex is the short form of MUTual EXclusion object. It is a locking mechanism as well as a special binary semaphore.

When a thread or process accesses the critical section of codes or a shared resource, it acquires the mutex of the resource and locks it. Once the mutex is locked, no other thread can access the resource, and they will be put in a queue.

Once the use of the resource is over, the thread unlocks the mutex and makes it available to other threads in the queue. In other words, the mutex is passed to other threads.

10 .

What is the use of Semaphores?

Semaphore is an integer variable that we use to synchronize concurrent processes. As a result, it helps to overcome the issues that occur because of race conditions. We also use Semaphore to solve critical section of codes problem since it acts as the signal to control processes or threads to access the critical section of codes.

Know that there are two types of semaphores: binary and counting.

11 .

What do you mean by IPC Communication?

IPC stands for Inter-Process Communication. Essentially, it is a mechanism that supports processes to communicate effectively with each other. Along with that, the processes synchronize their activities in many ways. However, shared memory and message-passing methods are vital in IPC communication.

In the shared memory IPC method, processes share some variables. Any number of processes can access the variables. In the message-passing IPC method, there are no shared variables between processes.

12 .

State the use of Frame Relay.

It is the packet-switching data transfer method with which we can transfer data between devices in LANs as well as WANs. Frame relays avoid retransmission as well as error correction in data transfer altogether. As a result, it performs high-speed data transmission. It is essential to note that frame relays use the datalink layer of the OSI model.

13 .

What do you understand by Clustered Index?

It specifies the physical arrangement of data stored in databases. Every table in a database has a single index value. We can use one or more columns in a table for indexing. Clustered indexes support fragmentation as well as crucial lookup functionality.

14 .

Define Empty Class in C++

An empty class is a class that has no data members. And the size of an empty class is always 1 byte. This is because an empty class requires only a minimum memory space as it has no data members. We can use an empty class as a placeholder for verifying purposes. Not just that, we can use it as an enabler for special functionalities.

15 .

What do you mean by Virtual Function in C++?

A virtual function is essentially a member function in a base class. We can derive virtual functions in the base class using the virtual keywords. We redefine a virtual function in a derived class to achieve runtime polymorphism.

Further, we can access virtual functions using object pointers. We use virtual functions to ensure that the proper function is called.

16 .

Brief Callback Function in JavaScript?

It is the function that passes an argument into another or parent function. A callback function is executed only after the parent function is executed.

We use callback functions to ensure some functions must be executed only after a specific task is completed. Not just that, we use a callback function to prevent errors due to the non-availability of data. The non-availability condition arises when the data is being used by another function, sometimes.

17 .

What is a MAC address?

The distinct 48-bit hardware address of a LAN card is known as a MAC (Media Access Control) address, and it is typically stored in the ROM of the network adapter card. A network card's or device's MAC address is a special identification number that manufacturers provide to certain items. It is often referred to as a physical address encoded in hexadecimal numbers. Every MAC address is distinct globally and is, in principle, set for every device.

There are six pairs of numbers in each MAC address. The first three pairs aid in identifying the manufacturer, and the following three pair names with particular models. In order to connect to networks, a computer may have a variety of devices. As a result, it is typical for a computer to have a MAC address for Ethernet, a Wi-Fi address, and a Bluetooth address.

18 .

What are the HTTP and the HTTPS protocol?

The HyperText Transfer Protocol (HTTP) establishes a set of guidelines and requirements for the transmission of information across the World Wide Web (WWW). It facilitates communication between web servers and browsers. Each command in this so-called "stateless protocol" is independent of the one before it. An application layer protocol based on TCP is HTTP. By default, port 80 is used.

The HyperText Transfer Protocol Secure, sometimes known as Secure HTTP It is a more sophisticated and secure variant of HTTP. SSL/TLS protocol is used to add security on top of HTTP. By encrypting the transmission, it makes transactions more safe and aids in securely identifying network servers. By default, port 443 is used.

19 .

Explain LAN (Local Area Network)

LANs are frequently used to link computers, laptops, and other consumer gadgets, allowing them to share resources (such printers and fax machines) and communicate. Enterprise networks are LANs that are used by businesses or organisations. There are two types of LAN networks: wired LAN and wireless LAN, which operate without the use of cables (achieved using LAN cable). These days, wireless LANs are widely used in locations where laying cable is challenging.

20 .

What is a 'frame relay' and in which layer does it operate?

Frame Relay is a wide-area network (WAN) data transmission protocol that connects local area networks (LANs) and uses the data connection layer of digital packet switching (WANs). X.25 and Frame Relay both use part of the same fundamental technologies. It was created to transfer analogue data as voice conversations and is based on the earlier X.25 packet-switching technology.

Frame Relay is a rapid packet technology, in contrast to X.25, which was created for analogue communications, hence the protocol does not make an effort to repair faults. It is frequently used to connect LANs to primary backbones, as well as in leased T-1 lines, public wide area networks, and private network settings. It is not suited for audio or video, which need a continuous stream of transmissions and require a dedicated connection during the transmission period.

21 .

How does a firewall work?

A firewall is a security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It acts as a barrier between a trusted internal network (like your home or business network) and untrusted external networks (like the internet), allowing or blocking traffic based on rules set by the user or administrator.

Here's how a firewall works:

1. Traffic Filtering

Firewalls inspect data packets (small units of data) that travel through the network. Based on the firewall's rules, each packet is either:

Allowed (permitted to pass through),
Blocked (denied access), or
Flagged for further inspection.

2. Types of Firewalls

Packet-Filtering Firewalls: Examine packets in isolation and allow/deny based on criteria like IP address, port number, and protocol.
Stateful Inspection Firewalls: Track active connections and make decisions based on the state of the connection as well as the rules.
Application-Level Firewalls (Proxy Firewalls): Analyze traffic at the application level (like HTTP or FTP), making more informed decisions about whether to allow it.
Next-Generation Firewalls (NGFW): Combine traditional firewall capabilities with features like deep packet inspection, intrusion prevention, and application awareness.

3. Deployment Types

Software Firewalls: Installed on individual devices (like antivirus with firewall features).
Hardware Firewalls: Standalone physical devices used mainly in business environments to protect the whole network.

4. Common Rules Examples

Block all traffic from a specific IP address
Allow only HTTP (port 80) and HTTPS (port 443) traffic
Block access to certain websites or applications.

22 .

What is IPC communications?

An independent process is not affected by the execution of other processes while a cooperating process can be affected by other executing processes. In other words, one might think that independent processes will run fast, conveniently, and modularly, but in reality, cooperative behaviour can be used to increase computational speed, convenience, and modularity. Inter-process communication (IPC), or inter-process communication, is a mechanism that enables processes to contact each other and synchronize their actions. Cooperation between these processes is accomplished through this communication.

23 .

What is Stack corruption?

When stack corruption is suspected, one should look at the local variables in the called and calling functions to see if the values passed are different from the values passed by the calling function. A stack corruption has occurred when a parameter seems to have a different value than the one that was passed. When a stack corruption is detected, one should look at the local variables in the called and calling functions to see if they may have been used as a source of memory corruption.

24 .

What is Deadlock?

A deadlock is a situation in computing where a group of processes become stuck because each process is waiting for a resource that another process holds, and none of them can proceed.

In simpler terms:

Imagine four cars at a four-way intersection, each blocking the others and waiting for the next one to move — but no one can move because they’re all waiting. That’s a deadlock.

In Operating Systems (or Databases), deadlock involves:

Mutual Exclusion – At least one resource is held in a non-shareable mode.
Hold and Wait – A process is holding one resource and waiting to acquire others.
No Preemption – Resources can't be forcibly taken from a process; they must be released voluntarily.
Circular Wait – A closed chain of processes exists, where each process holds at least one resource the next process needs.

These four conditions must all be true simultaneously for a deadlock to occur.

Example:

Process A holds Resource 1 and wants Resource 2.
Process B holds Resource 2 and wants Resource 1.
Neither can proceed, and both are stuck — this is a deadlock.

Ways to Handle Deadlocks:

Prevention: Ensure at least one of the four conditions never occurs.
Avoidance: Use algorithms (like Banker’s Algorithm) to avoid unsafe states.
Detection and Recovery: Let deadlocks happen but detect them and recover (e.g., kill a process or force resource release).
Ignore It: In some systems (like many desktop OSes), deadlocks are rare and may just be ignored.

25 .

What is Mem leaks?

When programmers create a memory in the heap and forget to delete it, the consequences are that the computer's performance is reduced because of the reduction in available memory, that is, the amount of memory that is accessible. In the worst case, too much of the available memory might become occupied and the application may fail, or the system might slow down radically. Memory leaks are particularly problematic for programs such as Daemons and Servers, which by definition do not terminate.

26 .

What is Priority Inversion?

When it comes to scheduling concepts in Operating systems, one of the foremost factors is Task Scheduling. There are numerous scheduling alternatives such as First Come First Serve, Round Robin, Priority-based scheduling, etc. Each scheduling approach has its own advantages and disadvantages.

You may assume that Priority Inversion is a task-based scheduling problem because it is listed under priority-based scheduling. It is a circumstance that occurs in priority-based scheduling when higher-priority jobs interfere with lower-priority jobs when possible.

When a lower priority task (L) is running and a higher priority task (H) also needs to run, a higher priority task (H) may be preempted by a lower priority task (L) in priority-based scheduling.

Now, assume that both lower and higher-priority tasks need to share a common resource (for example, a file or device) to accomplish their respective tasks. Here, task synchronization and resource sharing are required. Several techniques for handling such scenarios may be used, for example, mutex synchronization.

A task acquires mutex before entering the critical section (CS) and releases it after exiting the critical section (CS).

27 .

How will you find the time complexity of an algorithm?

Big O Notation is a method used to find the time complexity of an algorithm. It is essentially a mathematical property used to analyze and compare algorithms. Big O Notation tracks the asymptotic behavior of functions. This method can easily track the degree of growth and declination of a function.

Big O Notation measures the work a CPU can perform when the input size increases. Note that when the time complexity is low, the performance of the CPU is better.

28 .

Explain Normalization and De-Normalization.

Databases must be normalized in order to structure them efficiently. It involves establishing tables and establishing connections between them based on certain rules. These rules may eliminate or reduce the amount of redundancy and dependency, making it more flexible. 1NF, 2NF, 3NF, BCNF, 4NF, and 5NF are 6 distinct normal forms. Normalization should be done to avoid data loss but not at the expense of integrity.

The procedure of denormalizing a schema is to convert it into one that has redundant information. Redundancy and keeping redundant data consistent are both beneficial. An over-normalised structure is inefficient in query processing because of its overheads.

Frequently Asked Questions

1. How should I prepare to clear the Qualcomm interview?

You should be strong in computer fundamentals such as operating systems, DBNS, data structures and algorithms, and networks. You must be proficient in programming languages like Java, C++, and Python. Above all, you must sharpen your presentation, problem-solving, analytical thinking, etc.

2. What are the rounds of Qualcomm interviews?

There are totally four rounds – online test, online coding test, technical round, and HR round.

3. What questions would be asked in the Qualcomm interview?

In the online round, you will be asked questions with verbal, aptitude, communication, and computer fundamentals. You will be asked in-depth technical questions and coding problems in the technical round. In the HR interview, you will be asked about your family background, interests, education details, goals, and a few challenging questions to test your attitude.

4. Will Qualcomm interviews be tough?

Not at all. If you have prepared well, cracking the Qualcomm interview is very easy.

5. What are the top three mistakes that candidates make?

They are not confident enough to present precisely what they know
They don’t learn technical concepts in-depth
They provide either too many or fewer details in the resume and need to be more accurate with the resume details.

6. What would be the most challenging questions in a Qualcomm interview?

The questions of the technical round would be the hardest. You must be ready to solve critical coding problems. If you prepare well, there is no such thing as the most complex questions. You will have answers to all questions.

7. How to impress interviewers?

If you answer questions confidently and precisely, interviewers will be impressed quickly. Another main thing is that your attitude must be pleasing and polite. In addition to exhibiting your technical expertise, if you follow the pointers mentioned above, you will undoubtedly ace your interview.

8. Does Qualcomm pay well?

As per Ambitionbox, the average salary of a Qualcomm engineer in India is Rs 15.7 lakhs for employees with less than 1 year of experience to 5 years. The salary at Qualcomm ranges between Rs 11.5 lakhs to Rs 24 lakhs per year.

9. What is the Eligibility Criteria at Qualcomm?

* At least one bachelor's degree in engineering, information systems, computer science, or a related field or a proven history of experience in the technical field is required.

* You must be able to program in C, Python, Perl, Shell scripting, and/or makefiles and toolchains.

* You may also possess knowledge of makefiles and toolchains.