Iberchem interview questions

I received an invitation to an interview with the HR about 2 weeks after applying. This interview lasted about 30 minutes and was very thorough and informative. Following this, I received an invitation for an interview with the Manager, which was a more informal chat for about 15 minutes. I was told the third and final round of interviews would be on site at the company. Both of the interviewers were very friendly and professional, however I did not end up receiving an offer. I found the whole hiring process quite transparent, quick, structured and professional, except maybe a brief feedback rather than a generic rejection mail (especially for such a niche role, where the number of applicants are presumably limited) after going through 2 rounds would have been nice.