The hiring manager contacted me and performed a phone screen. Shortly after I was asked to come in for an in-person interview. I met with the hiring manager and a developer, and then had a second interview with the team lead and another developer.
I really liked everyone I met, and the interview process was casual and fairly relaxed. We discussed specifics of the role, as well as my background and experience. At the end of the interview the hiring manager indicated that he felt like they could benefit from my experience, and they would follow up after completing a few more interviews with other candidates.
The hiring manager followed up a week later, and indicated that the team felt I was technically capable, but had decided to pursue other candidates. My guess is they either didn't think I would be a cultural fit, or they would not be able to make a competitive offer, enough to entice me to leave my current position. Based on reported engineer salaries, it looks like I would likely have to take a $15-20k per year pay cut to work as a software engineer for On Semi.
The impression I got from the overall experience, as well as researching the company, is that On Semi runs their software shops on a very lean budget. So they're almost always understaffed and the staff that are on hand are likely underpaid based on salary averages. This is unfortunate, because the work itself is interesting, and you have an opportunity to get exposure to a lot of different technologies.
At the end of the day it's probably a great place for a new grad to gain some experience and network a bit, but I'm unsure of the potential for long term career growth.