From the New Yorker profile of quiet superstars Jeff Dean and Sanjay Ghemawat, "The Friendship that Made Google Huge" by James Somers, a hierarchy:

Today, Google's engineers exist in a Great Chain of Being that begins at Level 1. At the bottom are the I.T. support staff. Level 2s are fresh out of college; Level 3s often have master's degrees. Getting to Level 4 takes several years, or a Ph.D. Most progression stops at Level 5. Level 6 engineers—the top ten per cent—are so capable that they could be said to be the reason a project succeeds; Level 7s are Level 6s with a long track record. Principal Engineers, the Level 8s, are associated with a major product or piece of infrastructure. Distinguished Engineers, the Level 9s, are spoken of with reverence. To become a Google Fellow, a Level 10, is to win an honor that will follow you for life. Google Fellows are usually the world's leading experts in their fields. Jeff and Sanjay are Google Senior Fellows—the company's first and only Level 11s.

(cf Classy People (2000-04-01), LensManic (2001-07-16), ExtraOrdinary (2005-04-09), Life Partner Criteria (2014-05-15), ...) - ^z - 2018-12-12