I had almost forgotten Monee, the grinning old man who prepared our meal. [...] He was Po-Po's factotum--cook, butler, and climber of the bread-fruit and cocoa-nut trees; and, added to all else, a mighty favourite with his mistress; with whom he would sit smoking and gossiping by the hour.
2018 January 10, Ann Hornaday, "'Phantom Thread': In his final role, Daniel Day-Lewis reminds us he's a monumental talent", in Washington Post:
He lives with his devoted sister and factotum, Cyril (Lesley Manville), and a series of women who tend to be quietly eased out when they demand too much time and attention or -- heaven forfend! -- dare to speak during Woodcock's monastic creative routine.
Possibly directly or else via French from New Latinfactotum(literally "do everything"), from Latinfac, present singular imperative of faci?("do, make") + t?tum("everything"); attested in Dutch from 1605.