This was a month and a half - 2-month process total. Do not expect a quick decision, but I'd say it's good that they take the time to interview their candidates and deliberate accordingly.
First met with HR, only a 15-minute interview where they told me the salary range and expectations. A week later, I had a 1-hour interview with the Senior Acq Editor and 2 other Acquisition Editors. They asked me a lot of in-depth questions regarding the process, my experience, and other behavioral questions. If you had not had an Acquisitions position previously, or any editorial experience in general, you would have struggled for sure. They were very friendly, though, and it didn't always feel like an interview since we discussed a lot of initiatives within the company and our interests.
About 2-3 weeks later I was asked to meet with the Publisher, about a 45-minute interview which felt more conversational than anything. He made it very clear that by speaking with him I would likely receive an offer within the next 2 weeks, which I did and accepted. I enjoyed speaking to the publisher a lot (he was very straightforward yet kind) and I'm very excited to start this position!