The engineers reverse-engineered their competitor's product to improve their own design.

reverse-engineered 是动词 reverse-engineer 的过去式形式。reverse-engineer 由前缀 reverse-（表示"反向"）和动词 engineer（设计、建造）组成，字面意思是"反向设计"，即通过拆解成品来研究其工作原理和设计方法，也就是"逆向工程"。