There are advantage and disadvantages to both:
If you hire from the outside the person has to be trained up on the new company’s way of doing things. The person also has outside perspective to look at something the new company does and say “that’s stupid, we should do it differently”.
Hiring from the inside allows someone to be slotted in faster, but often that person has been gunnel visioned into that company’s way of doing things, so you don’t know if there are better (or different) ways of doing thing.
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