This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
If someone asks me this, then I'll find out the background experience that person has. A mainframe expert like you would be proficient in dealing with batch centric jobs. As Ranganathan put it, SAAS has a broad meaning.
In my opinion, mapreduce and big data management has got more in common with mainframe people than cloud centric environment.