Applied online, had a phone screen, then had an interview with the hiring manager and then their manager. After this did a presentation assignment. I did not hear back for several weeks until I followed up. HR then indicated they had gone with another candidate, but the hiring manager indicated there was a miscommunication and asked to speak with me. They then proceeded to tell me that the presentation did not go well, and asked for my thoughts on that. They also indicated something along the lines of an offer going out to someone else, but nothing was finalized, though this was unclear and I received inconsistent answers when I questioned it. I then did not hear back for a month, until I followed up one more time to close the gap and was told they went forward with another candidate.
To be clear, my issue is with the lack of communication, and the misleading nature of asking to meet with me again (which makes it seem as though an offer may be given). Having to follow up so many times after interviewing and doing a presentation shows how little they respected my time. Also, if you're going back and forth that much over a candidate, then they're not for you and you shouldn't keep them on the hook.