The interview process consisted of:

• One phone interview
• Four one-on-one face-to-face interviews
• One follow-up phone interview

The recruiter informed me they were concerned about my system design skills. They offered me another opportunity after the on-site interview, after which they stated I had performed well but decided to interview me one more time on system design.

Two days later, however, they called again and canceled the second follow-up interview. I was somewhat upset as they had promised another interview, but all I can do is move on.

Add up two big integers represented in arrays.

Design a system to support Facebook status updates.

Design the recommendation system for search keywords.