Without any discussion about what I do I was given a cut-pasted question where the focus was on syntactic nits of C instead of understanding of the higher level skills of algorithms or compiler design. The interviewer seemed unsure of his compiler knowledge because he didn't have much.
Mine was a better high level solution than the interviewer had anticipated, but they seemed disinterested to engage beyond their narrow experience and scope which should have been evident from the cookie-cutter manner the problem was cut and pasted. These questions may be okay for a entry level engineer but not for someone with extensive algorithm and compiler design experience.
I applied with a strong internal referral but still the recruiter didn't sound very enthusiastic, so may be the company doesn't have sound engineering processes. The interviewer sounded snippy, like he just wanted someone to do what they were told, instead of really looking for long-term growth or skills.
Overall, a poor fit for me and I couldn't see myself working for the interviewer located in Austin who was supposedly a lead but lacked strong compiler skills.