従事
じゅうじ · juuji · JLPT N1 · noun
following
従 (follow) + 事 (matter, affair) = pursuing a matter: engaging in or following through on your work
従 means to follow or obey, and 事 means thing or affair. Put together, 従事 is following through on an affair, so it means engaging in or pursuing a line of work or duty.
事 — hand 又 holding a banner/tablet on a pole
Originally a pictograph of a hand (又) grasping a pole or ceremonial banner used by an official, depicting the act of conducting court business. From this it came to mean 'affair, matter, business, service.' It shares an ancient origin with 史 (scribe) and 吏 (official).