Software developers are the engine behind the design, development, installation, testing and maintenance of software systems.
Much more than writing code developers are expected to play an important role in in making the business more effective. A software developer is expected to interact with business and play in integral part in designing (in as much) the business as the technical solution.
The skill in this is creating the code to link systems together.
As a software developer you are expected to enter a code-base and not only complete the necessary work, but leave the system in a better state than when work began. As an example, keeping software upgraded to the latest version, adding missing components to source control, and adding unit tests to prevent degradation of the codebase in future releases.