factotum -- Jack

fac·to·tum  (fk-ttm) n. An employee or assistant who serves in a wide range of capacities. [Medieval Latin facttum : Latin fac, imperative of facere, to do; see dh- in Indo-European roots + Latin ttum, everything, from neuter of ttus, all; see teut- in Indo-European roots.]

The American Heritage® Dictionary of the English Language.

When Jack gets his first job, he may have to be a factotum like so many people new to their profession are.