i was asked technical questions first, and then when i did not know how to answer those they started asking about my previous experience and went on with general personal questions.

The interview process was actually fantastic and went very smoothly. I was offered the job I'd applied for and was in the closing stages. The reason for the poor feedback is due to the fact that Coherent retracted their offer very suddenly for vague "financial reasons", and asked my job recruiter to deliver this information instead. This was a major blow and derailed the other interviews I had lined up, as this offer was essentially a guarantee. Highly unprofessional from an otherwise excellent company.