As a weapons engineer, you design test, analyze, update, and improve military weapons systems, such as missile defense systems, fighter jets, body armor, and conventional weapons. Your duties depend on the type of industry in which you work. Many weapons systems are now very complex, requiring numerous systems and parts. For example, a fighter jet involves input from aerospace engineers or guidance systems design experts and optical engineers. However, many of your responsibilities are the same across industries. You work with teams of engineers in consultation with military experts to identify weaknesses in weapons and prepare prototypes before beginning full production.