This was a two-round interview process. I received an email from the hiring manager within a few days to set up a phone screen. We had a quick ~30 minute chat about my resume, skills, and career goals. Typical stuff.
Maybe a week later I was contacted to pick an interview time slot. The interview was a panel interview on Zoom with like 6 people, mostly engineers except one physicist. The first part was a technical presentation of a subject of my choice - could have been anything as long it "showcased why I was a great fit".
The presentation went fairly well. They asked a lot of questions, using my presentation to probe at my technical skills, like I expected.
The next part was just the panel asking me various on-the-spot questions on my background, technical questions, etc.
Finally, they gave me a programming skills test. I had the choice of Python, C, or C++, and was asked to review a chunk of code and a unit test as if it were a code review. Next, they asked me to modify the code based on my comments. It was a pretty easy exercise for anyone with coding experience.
Overall, it felt like a relaxed conversation. After I got over my initial nerves, it wasn't that bad.