The HR and communication is friendly.
1st round - discussion with HR and a small coding round
2nd round - Interview with a manager and few questions asked around Virtualization, SQL, C++
Due to COVID, rest of the rounds were virtual and scheduled on the same day.
3rd round - Design. This is where it went haywire. Not because of the design question. Infact the interview was very happy with my design. In the last 2 mins of the interview he asked "Do you know HTML and frontend development" I said NO, i am a backend C++ developer, to which he responded he needs someone with front end knowledge and rejected me instantly.
The HR and interviewers should read the job description you post on your own website before interviewing candidates.
HR called me to apologize and said "there was some internal miscommunication". and i got another generic mail with rejection without any mention of the reason. There is no accountability it seems.
Just like you, i have also invested my time for your company. Its OK to reject someone but its NOT OK to reject someone for wrong reasons and asking for things not even mentioned in your "job description"