Conversation so far:
when did Xi Jinping join the politburo standing committee?
in October 2007.
what was Xi Jinping role in the politburo standing committee?
Xi Jinping is the general secretary.
what were Xi Jinping's contributions as general secretary of the politburo standing comittee?
Xi Jinping vowed to crack down on corruption.
was Xi Jinping succesful in his nationwide anti-corruption campaign?
Within the first two years of the campaign alone, over 200,000 low-ranking officials received warnings, fines, and demotions.
did Xi Jinping have other contributions besides his succesful anti-corruption campaign?
Xi Jinping has taken a very strong stand to control internet usage inside China, including Google and Facebook, advocating Internet censorship in China as the concept of internet sovereignty.

Question: When did he become president?
Self-contained rewrite: When did Xi Jinping become president of the People's Republic of China?