I applied through a recruiter.

The person doing the initial interview postponed the interview twice on very short notice. She also only confirmed the final date/time on the day it was supposed to take place, after I messaged the recruiter to ask them if it would go ahead or not. This already looked very unprofessional.

Then, during the virtual interview she did not have her camera on (she only turned it on during the last minute of the interview) which I find a bit rude to be honest. She also started the interview not by giving an overview of the company but rather by asking me if I had any questions. Usually this would come at the end of an interview. This already gave a very bad impression of the company.

The second interview was with someone else and was much more professional. It was a live coding interview via Coderpad. I finished everything in time and had the impression it went well. However, I did not get invited to the next stage. I only found out about this by receiving an email for a feedback form titled "Feedback after the hiring process". But the email itself did not mention that I didn’t make it into the next round. Again, this seems quite rude.

Small coding exercise via Coderpad, you can use Google if you need to look up something (e.g. the parameters of a numpy function you want to use).