engineers do not only work with machines. they also work a lot with other people. many engineering projects are large and very complicated. often different kinds of engineers work together and help each other. as an example, computer engineers need help from electrical engineers to build a computer. the computer needs programs written by software engineers. the computer could be used by aerospace engineers to control an airplane. an airplane is a big mechanical system with many parts, so a mechanical engineer and a systems engineer are also needed.