First, some clarification--software engineers develop algorithms and solve generalized problems--while they can write the code that generates a particular computer program, it is not likely to be their main job. Software engineers can work for a large company and can project growth in order to sell an organization a program. They can also be involved in setting up networks between computers in an organization and creating firewalls for added security.
Software engineers have a massive societal impact. Computer hacking software is quite sophisticated and engineers work to encrypt data so that it does not fall into the wrong hands. Engineers also discuss ways to secure electronic transactions such as purchases made on the Internet or in a store using a credit card. Software engineers convince businesses of their need for software in order to ensure growth--this growth drives the local and national economy as businesses hire more people to work with the software.