Aperi interview questions

The CTO was diplomatic and but confusing me, the job specs were about C++ programming and his questions were about web-layout design which happened me to have done well such projects in the last years. I met then the CEO, which spoke well English but I doubt he thinks in English the good social manners, cynical to my past experience. Followed a coding exercise which was trivial in nature but I did not foresee their intention, I wrote it immediately, instead they expected to be the best performance solution for execution speed and CEO was sly in interaction trying to teach me things which I knew but I did not expect they looked for, mentioning what I did is exactly what they do not do there. For instance one way is to process data with minimum memory another way is to use highest execution speed and generally both cannot be met at once and I did not know what they looked for. Then the CEO scanned my resume for skills and asked me to evaluate myself from 0 to 10 and how many years I have worked with them.