It started out well, but then after we discussed my salary requirements, I assumed we were in range since it went to two additional interviews, after which I never heard back. Through my network I learned the salary was far below (and not in line with regional standards). That was a huge waste of time and a disappointment.

Poor process. Ghosting is pretty common and the whole process is unprofessional. It's also very long. The people interviewing have no experience with interviewing and they also have no idea what the expectations are about the role.