lǎo​sī​jī

old hand

老司机 老司機 lǎo​sī​jī
old hand
(slang) an experienced person; a veteran with extensive knowledge or skill in a particular field
Internet veteran
(slang) a person who shares or is an expert in finding illicit or pornographic content on the Internet
experienced driver
an experienced driver; one who has been driving for a long time