The best part of firmware/embedded engineering is that you work with others to create something from nothing (ie new hardware or products). Those applications that we all see from a user perspective cannot exist without us. We create the building blocks/foundations that application developers take for granted. For example, I work in the OS and file system logic layers, so when that user hits save to save his data, it is my logic that makes that saving possible.
We are the first layer between that new hardware, and the user. We are 'On the Metal", Just make sure you done get a cut!