I had applied a number of times online but didn't get any response from HR until I had an employee referral. The process then moved very quickly. From the time I received my first email from HR to my on-site, in-person interview was 7 days. Several emails were exchanged with HR, followed by two phone interviews.

The first phone interview was with the hiring manager. This was a pleasant 30-minute conversation that included some high-level technical questions, but nothing too serious.

The second phone interview, held two days later, was with three members of the hiring manager's team. They provided a link to a website where I could write code in real time while they observed. This platform was used during the approximately 45-minute interview as they asked technical questions.

Following this, I was asked to fly out to Cupertino for an on-site interview.

Interviews were scheduled from 10 am to 5 pm, with a 1.5-hour block for lunch starting at 11:30 am. Most of my interview sessions were either 30 or 45 minutes long.

The first session was with two engineers who immediately began asking various coding and technical questions. I then had a one-on-one session with the hiring manager, followed by a few more sessions.

During the lunch break, two engineers escorted me to the cafeteria. We took our food to go and proceeded to a conference room, where the interview continued. I was unable to eat much as I was busy talking.

When they concluded, the HR representative informed me that my skill set did not match their requirements and I was free to leave. My interview was scheduled until 5 pm, but it was only 1 pm. Needless to say, my ego was a little bruised.

Write your own version of atoi().

Explain how RS232 works from a hardware level. What are the areas of concern when writing firmware to drive an RS232 UART when strictly using GPIO pins?