Slack interview questions

The first round was a general discussion round with HR. Then second round was again a discussion round to know about my skills and to evaluate whether my skills and my profile matches with the job requirements or not. During second round I was surprised to see that interview questions were completely irrelevant to the job profile. After the interview process I has written to Human Resource team also that interview question were irrelevant to the job profile I applied for. Additionally, it was nowhere mentioned about incident response in the job description when I applied. The complete job description was about DevSecOps Engineer. Incident response team specialisation is completely different then DevSecOps Engineer. But HR team also didn't respond to my email. Overall the interview process was very disappointing. I never expect such type of irrelevant interview questions from Slack company. If they have to reject my profile, then they can reject it directly. I wonder why they organise such a fake interview process just to waste the time and to disappoint the candidate with irrelevant questions.