In the business world, he's known as a ruthless cutthroat who climbs the ladder at others' expense.

cutthroat 是由动词短语 cut throat（割喉咙）组成的复合词，字面意思是"割喉"。在商业语境中，这个词用来形容"残酷无情的竞争者"，比喻为了成功不惜伤害他人的行为方式。