Veeva Systems Senior IT Engineer - Sydney interview questions

The whole Interview process took 8 weeks. Went through 4 interviews in 4 weeks, then they did reference checks. Then they said they need to get Global CEO to approve for letter of offer. Veeva has more than 2000 staff and it doesn't make sense to get top CEO approve for low level job. Then after 3 weeks I was asked to do 5th interview which i had to wait for another week. Either something wrong with their process or lack of communications OR something was not right. Very frustrated and learnt my lesson. Watch out for American companies. I turned down 3 jobs from 3 different companies as i had impression that i would be getting letter of offer since they started reference checks which they were happy with.