I applied through a recruiter. The process took 1 week. I interviewed at Apple in Dec 2017
Interview
Most unprofessional interviewer I've ever had.
I was contacted by a recruiter for the position and shortly after scheduled the interview. He didn't tell me much about the job and sent me a very wordy job description for what appeared to be a senior engineering position. I had to schedule my interview at the end of the day since I had a few before it, but they were accommodating.
My only interview was with a senior manager. The first red flag was that he called over an hour late, after I had already given up on the interview. He did give me an option to reschedule but I declined since I wanted to get it over with. Next was resume/experience questions but the interviewer was extremely rude and unprofessional and didn't understand my explanations.
I was then asked two questions on coderpad which were not too bad, but obscure. As I worked through it, the interviewer continued to make snide and unprofessional comments. At the end of the interview, the interviewer laughed, cut me off mid sentence, and hung up the phone.
Overall this was the most negative interview experience I have ever had, especially from any of the top 10 tech companies. I was happy to not receive an offer since I would never want to work with such a toxic manager, or a company that would promote his behavior.
I applied through a recruiter. The process took 5 weeks. I interviewed at Apple (Cupertino, CA) in Apr 2016
Interview
I was contacted by one of their recruiters via LinkedIn. Then I had two different discussions via phone and an onsite interview.
The first discussion was with the recruiter. It was a short talk where I introduced myself and the recruiter presented me the job and some details about the IMG group. She didn't tell me anything that wasn't already on the job description. I was also very surprised that she asked me to give names for the clients of the company where I was working back then. I found it very unprofessional. I told the recruiter that this is confidential information and I cannot give any names apart from those already mentioned on the website.
The second one was a technical interview with the hiring manager. It took half an hour but it was unbelievably efficient. I was asked questions about my work, about problems that I had to solve and I had to do some GPU coding.
Next I was invited for an onsite interview in Cupertino. The onsite interview took two days.
In the first day, I had discussions with four persons. One of them was the hiring manager. The interviews from the first day covered subjects related to C, binary representations, parallel access to data structures (queues, if I remember correctly) and then GPU related topics: reduce, histogram, implementing a global memory allocator.
In the second day, I had interviews with three persons. The subjects were related to GPU algorithms and GPU architecture.
All interviewers had been very professional, but most of them were lacking any enthusiasm and seemed very indifferent. No one told me anything about their team and the project. Of course, I was given the option to ask questions: 5 minutes after each interview. But still I was also expecting a brief introduction from their side.
I had some trouble understanding what one of the interviewers was saying. He seemed to have some small difficulties talking and a non-American accent. I had to ask him to repeat the questions many times and that made me very stressed and nervous. I didn't manage to answer all his questions.
Apple has many offices in Cupertino. For the one where I had the interviews, each day I had to wait outside the building for my first interviewer to come and open the door for me. You can't enter the building otherwise, you're not allowed to, and there's no waiting room. So be prepared in case it rains outside.