Conversation so far:
What was Marissa Mayer's relationship with Google?
She joined Google in 1999 as employee number 20.
What was her position/title?
She started out writing code and overseeing small teams of engineers.
Did she have success in this job?
She became known for her attention to detail, which helped land her a promotion.

Question: What did she get promoted to?
Self-contained rewrite: What did Marissa Mayer get promoted to at Google?