Arm New Grad: OS concepts screen, then Reverse Bits, a Rate Limiter design and caching questions

This was one of my first interviews but I had spent 9 months preparing for it so I had high hopes going into it. The overall process took three weeks with three separate stages.

1. HR phone screening with simple behavioral questions which discussed my resume, projects I had worked on and why I wanted to work at Arm.

2. Virtual technical interview which was 30 minutes long. I was asked technical concepts around operating systems like how to manage processes and memory. It's ok not to know the answer, but it is important to demonstrate your thought process.

3. The last stage was a 90-minute technical interview where I was asked a LeetCode, HLD, and more technical questions.

   1. The LeetCode question was Reverse Bits which felt like a gotcha kind of question because I think it's one of those ones where if you've seen it before you'll pass but if not it's really hard to get it on the spot. Fortunately, I had seen it before so I was able to get all the tests to pass.

   2. The system design was to design a rate limiter which was nice and easy and the interviewer was really thoughtful and clearly knew a lot.

   3. The remaining questions were all about caching and stuff like what makes a good cache key.

The recruiter reached out with an offer the day after my final interview so it will be fun starting. I recommend doing as much OS and caching prep as possible along with DSA so you are prepared for whatever they ask because without the long prep time I don't think I would have passed.