Transporter technology utilises engineering principles. It figures in that sense.
Besides, he said in an episode that when he enlisted he studied engineering. It may also have been chance. Perhaps as a young enlisted man, the Cardassian war broke out and he had to learn to be a tactical officer and a soldier. As a related point, I'd bet Nog never thought he would be a soldier and kill Jem'Hadar when he signed up, but such is life.