Several parts combine into one character.

仕 is a compound ideograph: 人 (person, written 亻) + 士 (scholar). The picture is a literate man bowing in service to a lord — "the scholar attends his superior." In old China, taking a government post was called 出仕 ("going out to serve"), and from that ritual the character drifted into the broad meaning of "to work."

Korean reading "sa." Used only in formal compounds: 奉仕 (bongsa, voluntary service), 仕官 (sagwan, taking office), 出仕 (chulsa). The everyday Korean word for "work" is (native) or (workplace) — 仕 itself feels archaic.

Mandarin shì, 4th tone. Even more archaic in modern Chinese: 仕官 (shìguān, ancient officialdom) and 绅士 (shēnshì, gentleman) are about all you meet. Spoken Chinese uses 工作 (gōngzuò) for "work."

Japanese is where 仕 lives most loudly. On-reading シ powers 仕事 (shigoto, work / job) — quite literally one of the first hundred words a Japanese learner meets — plus 仕方 (shikata, way / method), 奉仕 (hōshi, service), 給仕 (kyūji, waiter). Kun-reading つかえる (tsukaeru) means "to serve": 会社に仕える, "to serve a company." The compound 仕事 (仕 attend + 事 matter) is purely Japanese — Chinese says 工作, Korean says 일.

Memory aid: a person (亻) standing beside a scholar (士) — attending, serving, working.