Very unhealthy interview process:
Interview was for senior position(7+ years), but the person who was taking interview was a junior employee(around 3 years)(checked his profile on LinkedIn). I am not saying that juniors should not be encouraged to take interview but he should be experienced enough to discuss some of points which you are explaining. If he is not experienced enough then discussion will become argument since he will be arguing with you on SILLY POINTS.
When i share this feedback with HR, she was defending their interview process.
Also they will not bother to inform you about the interview result,