勤 (Kanji for be employed at)

Onyomi

KIN

The dudes who came from China to be employed are hella strong and KEEN on working.

( に ) つと*める	to be employed at xxx company (emphasis is on the physical work rather than the role). (used only about a job, and not in reference to a particular project at that job) ★★★★☆
つと＊め	my duties, my job ★☆☆☆☆

通勤(つうきん) する

commute ★★☆☆☆
通 (pass) + 勤 (be employed at) = 通勤 (commute)