3 stages: phone interview with recruiter, video call with director, then an on-site series of panel interviews.
Overall, it was a very negative experience. Every person I spoke to made at least one negative comment about how long I'd been looking for a job (e.g., "Wow, that's a long time"). This would be rude in any context, but in the horrible job market we're currently in, where many engineers are struggling, it's especially bad. It generally gave the impression that they wanted to make an already stressful process feel even worse.
Without a doubt, this is the worst interview process I've ever experienced.