I interviewed for 2 separate but similar Firmware Engineer positions at Western Digital, once in late September and once in early November 2019.
The interview process was similar for both positions: a 30-min to 1-hour-long phone screening with either the HR rep or one of the managers for the role, followed by a 3-hour-long on-site interview. The on-site I had for the first position consisted of 3 2:1 panels-style interviews, where they drilled into my knowledge of C and C++. I also had to explain what I did at my current company several times, as a few of the interviewers did not understand the purpose of the work I had done (maybe that's one of the reasons why I was trying to leave the company). They also asked me questions regarding operating systems and multi-threaded environments. For the most part, the interviewers I met with were pretty friendly, though I botched a few of the interview questions. About a week after my on-site, my HR rep let me know that I wasn't selected, but what was most annoying for me was that they had chosen an internal candidate for the role... I'm not really opened up interviews to outside candidates like me if they were going to fill it with a pre-existing employee anyway.
Fast-forward a few weeks, and my HR rep contacts me saying that they have another opening for a similar role with a different team. I accept, and go through the phone screen with the manager of that team. A few weeks later, I come in for the on-site interview, which now consisted of 6 1:1 interviews, about 30-45 mins each. Every interviewer asked about my experience and resume, which became a bit of an annoyance by the end of the interview. Most of the interviewers asked me technical questions, from general C/C++ questions to algorithm questions to even a riddle for me to solve. Again, most of them were quite friendly, and this time they even provided me with lunch, which was nice. However, a few of the interviewers interviewed me over the phone, so it was harder to understand what they were asking of me. Overall, I felt that I had done much better during this second interview than my first on-site visit.
Unfortunately, I didn't hear back about this position for another 2 months. Yes, TWO MONTHS. At least my HR rep didn't completely ghost me and gave me a solid answer, but 2 months for a response after a lengthy on-site interview is pretty ridiculous. On top of that, he had told me that they chose to move forward with a candidate who had ~10 years of experience... and I only had about 1.5 at the time. If they were going to hire a candidate with that much experience, why did they even bother interviewing me? What chance did I have against a candidate with that much more experience than I?
Overall, even though my on-site visits were more positive than negative, the way they handled my candidacy after the interview was incredibly fumbled. I won't be applying to Western Digital again for at least another few years, and even then I'd be really wary about them.