Why not 'his' job?
because "une amie" is a woman.
I could tell it was "her" right away. However, I have no idea why it is used "vient" (present tense) when the English translation is "lost" (past tense).
In French, "venir de + infinitive" translates "to have just done ....(the action the infinitive verb indicates)." So,
"Je viens d'expliquer" translates as "I just explained"
"Vous venez d'arriver" as "You just arrived"
I think 'il vient de faire quelque chose' means 'he just made something'? Can anybody explain?
Yes, that's right. the English construction with "just + preterit verb" does not exactly translate in French, so you have to use the typical French construction "present venir de + infinitive verb".
Excellent explanation. Thank you