Before the interviews, I was checking the reviews here and saw that many candidates got ghosted after several rounds. The same happened to me. Overall, my experience during the interviews was positive - I had a very good conversation with the HR manager, which led to a good chat with the hiring manager. In my opinion, both went well. However, I have never heard back from them, and now it has been a month of silence. I did follow up with HR after some time, but heard nothing back. So yes, this definitely seems very unprofessional and disrespectful. It is a shame to see this in such companies, and there are no objective excuses for this. Disappointing.