Me postulé en línea. El proceso tomó 4 semanas. Acudí a una entrevista en Qualcomm (San Diego, CA) en feb 2011
Entrevista
Overall Qualcomm is very organized. And Very professional
Interview Process:
Applied Online
After about two weeks HR e-mail me to set-up phone interview. Then I had a phone interview on same day.
During Phone interview key question I asked is "do you have any concerns about me?" He told me he wants some body committed to position at least two years. Also He told me he will set me up for onsite interview.
After another week HR e-mail me for on site interview.
On site is with 1 HR and 5 Engineers on same department
HR Will ask you how much money you made in previous job. Why you want to quit the job (I was currently employed), why you want to work @ Qualcomm, your future goals...
Then the fun starts with the five engineers.
Each interview takes about an hour. Lunch is also an interview.
Each interviewer is very professional; however they will test you until you break to see how you handle. Based on my experience they're not testing to see if you know everything, it's more of testing your personality, and how your problem solving skills.
My advice is making sure you know every word you on your resume. If you don't know the answer or don’t understand the questions, ask them questions. They were in our seat long time ago. They know what we going thru. Don’t give vague response that doesn’t really answer the question. They’re looking for short answers with the correct keywords. Not an essay answers.
Before ending the interview make sure they can tell what are your strong points and weak points.
Don't feel bad if you lose confidence after interview. That's normal for Qualcomm interviews. It’s like the last day of finals. You will be burned out by end of day.
Good thing is 90% of questions will be based on what you put on your resume, while 10% will be problem solving skills.
After onsite interview in two weeks HR called me saying “Congratulation and they will contact people I put as reference” That mean pretty much you got the job. Unless your reference don’t give good recommendation
Then about week later HR will wants a copy of your degree. That’s it. After that you get an offer?.
They don’t really have much room to negotiate. Initial offer is very competitive and attractive.
One of the things I did is I wrote thank you letter after phone interview and onsite interview. I only knew HR e-mail. So I wrote to the e-mail to HR but I addressed everyone. You should do that too. I am not sure if it helps, but it certainly doesn’t hurt.
Preguntas de entrevista [5]
Pregunta 1
Programming Related:
* what is the keyword volatile, static, const do?
* where do static data reside in memory?
* What are some ways to pass data into a function? and what the advantage and disadvantages?
O/S Related
* What makes an OS real time?
* Difference between Semaphore, Mutex, and spin locks?
* What is priority inversion, and what are methods to avoid it?
* If processor has a FP unit, is it ok to use FP inside kerenel? why/why not?
* What is is the difference between Non-blocking vs blocking calls? What are the benefits of each?
* How would you execute a non-blocking call in kernel?
Debuggin Related:
* What is stack trace?
* What data get pushed into a stack when jumping into a function call?
* Give some example you would use a scope to trouble shoot software problem? What line would you use to trigger the scope?
I/O Interface Related:
* Explain UART communication protocol?
* What signals are connected to DB9 connector, and how are they beeing used?
* What are some ways UART could have communication error?
* Explain I2C Communication protocol. How the Start, Stop condition generated? How do you select which device to communicate when all the devices tight to gether?
* Explain SPI Communications.
Programms to Write:
* Find what's wrong with this function?
void copydata(uint8_t *datato, uint8_t *datafrom, int size)
{
uint8_t *CurrentAddress = datafrom;
uint8_t *StopAddress = datafrom + size;
for(;CurrentAddress <= StopAddress;CurrentAddress++)
*CurrentAddress = *datafrom++;
}
* Write algorithm to find missing element in array. For example
int array[5] = {1, 2, 0, 3, 4};
this array should contain # from 1 to 5. # 5 is missing.
* find a element in array size of n using binary search method.
* Write a small program that add element into linked list at beginning of the list, and back of the list?
* Swap the bit order in a byte (example bit 7 would goto bit 0, bit 0 would goto bit 1)
* Write a small test program that would test the read/write memory? What good value to write if you want to test if there two data lines tight together?
Puzzles 1:
You have rope that take 60 min to burn. Speed of burning is not uniform. Example: it doesn't take 30 min to burn half
Using two ropes, how would you get 45 min?
Answer:
First Rope. Burn both ends at same time
Second Rope: Burn only one side.
when First rope is totally burn, it's been 30 min, now burn the rest of second rope both ends. Which should take additional 15 min.
30 + 15 = 45 min.
Puzzle 2:
There is a guy in a boat holding a rope that's tight to a Top of pole in the shore. He keep pulling the rope until he reach the shore. What is the speed relationship between amount of rope he pulls, vs horizonal speed? Which speed is higher?
Answer:
Horizonal speed is faster than the amount of rope he pulls. (Horizonal distance he travel is higher than amount of rope he pulls, by triangle theory where sum of two sides must be greater than 3rd side)
Puzzle 3:
in Analog Clock, It's exacly 3:00 Clock. What time would the Hour hand, and Min hand would overlap each other?
This is from my friend who had a kernel development position interview. This is only phone interview.
This is just from a phone interview:
How did you port uCOSII to the product?
How did you verify the worst case time delay?
What are the key features that you are looking for the RTOS?
(I mentioned the size, semaphore, event flags, and priority inheritance)
What are cache write back and write through? give examples in what situation you use which?
What are the major difference for the MCU and processors you are using?
What are the top considerations you pick those processors or MCU?
What are the programming model difference among those processors?
What is volatile? examples of using it.
A programming question:
int32 multiplication( int16 a, int16 b)
a "*" operator inside the func only takes 8 bit operands. what's the implementation?
(I was a little bit stuck on the sign bit)
What's the difference between DSP and MCU?
(I guess he was looking for the Harvard architecture, I didn't get that until he mentioned that)
What is the difference between desktop programming and embedded programming?
This is for DSP Position phone interview
Today I got phone interviewed for the DSP team. The scheduled time was 30 min, it went to about 50min, mostly because I talked too much, which is not very good thing.
The first half an hour, he asked me a lot of questions on my resume
1. How did you port rtos?
2. what was the precise timing control?
3. How did you improve FFT?
...
In the second part he was focused on comm and dsp concepts,
how to implement a FIR
how to implement a filter with FFT?
if PLL has statibily issue, where to look?
Cell phone power control down to the radio power and already in the min power, how to reduce the interference to others?
In signal space, the modulated signal got closer and closer, how to get better demodulation?
The interview had four steps and all steps are technical. The interviewers are very friendly. Various questions from IPC, Multi Threading, Linux, RTOS and CS. Linear and non-linear data structure.
Preguntas de entrevista [1]
Pregunta 1
Write strstr() code.
Solutions to avoid race condition?
Me postulé en línea. El proceso tomó 1 día. Acudí a una entrevista en Qualcomm (Boulder, CO) en feb 2024
Entrevista
I had applied through Qualcomm's job portal and then a team member reached out to me.
After asking if I was still interested he got me in touch with an HR to schedule the initial interview. It was pretty quick.
First round consisted of resume review and basic C questions such as bit manipulation and pointers.
Preguntas de entrevista [1]
Pregunta 1
They asked me about an RF Transceiver interfacing project that I had worked on.
Me postulé en persona. El proceso tomó 3 semanas. Acudí a una entrevista en Qualcomm (Tel Aviv) en sept 2022
Entrevista
After being informed about an upcoming salary offer, I received a call from another team leader (in the same group in Qualcomm) who requested that I meet with him for an additional interview. Confused by the sudden change, I decided to contact the hiring manager to inquire about the situation. To my surprise, the team leader who had initially contacted me reprimanded me for "circumventing authority." What was supposed to be a face-to-face interview turned into a bewildering and disheartening scolding session. Ultimately, despite being assured that it was merely a step to determine the specific team placement, I did not receive the promised job offer.
Later when I tried to call again to the hiring manager (who promissed that anyway I'll recieve salary offer) - he ignored my calls
