IPA: /kəmˈpjuːtərist/
KK: /kəmˈpjuːtərɪst/
A person who uses or is enthusiastic about computers and computer technology.
As a computerist, she spends hours exploring new software and hardware.
Computerist → The word is formed from "computer" (from Latin *computare*, meaning to calculate or count) and the suffix "-ist" (meaning one who practices or is concerned with). A computerist is someone who works with or specializes in computers.
Think of someone who 'calculates' or 'counts' ('computare') and is a 'practitioner' ('-ist') of that field — that's what a computerist does.
No commonly confused words.