I had 3 rounds of interviews. The first was with HR, second was with a Systems Engineer, and third was with the CIO and multiple Systems Engineers. I felt like I overall did pretty well in the interviews but did not receive an offer, which is fine. After not hearing back for a week, I sent a follow-up email asking what the timeline would be like for their decision and did not hear back. Pretty awful to not be able to take 5 minutes to tell someone you weren't interested in them when they had to spend hours prepping and doing multiple rounds of interviews with you. Definitely a red flag.