Google SoC Computer Architect interview questions

I had a phone interview and 5 interview rounds on-site. Most questions were on SoC, Computer Architecure, and modeling/simulators, energy/power/performance techniques. One interviewer gave me a couple of coding questions which were relatively easy (after I wrote them, he focused on how a particular cpu, cache, memory would affect the programs performance and given some configuration option what would I do). I did really well in all interviews (even the interviewers said so or implied it). However, the rejection call came 4 weeks later. If I had to guess, they went with a PhD or more experienced engineer since most people in the team are very experienced engineers that have worked in the field for 15-20+ years. Overall, I feel they literally just wasted my time. Sad but true.