Visa Inc. Staff Software Engineer interview questions

Applied for Staff Software Engineer position online using VISA carreers site. Got call from recruiter after 1 week. Talked briefly about my skills and experience and scheduled series of interviews. went through 8 rounds of interviews.

had 3 rounds 1st technical round conducted by a senior software engineer general questions on Data Structures, Algorithms, OOPS, 2-3 puzzles 2nd managerial round about yourself, questions on software development life cycle, integration and unit testing, SQL 3rd again technical round. This was taken by a big-shot who came all the way from California. He was the head of mobile development! given two files, find data that in there in file 1 but not in file 2, hash tables, encryption and compression related questions