One possibility might be DevOps Engineering (System and/or Network). Another possibility might be Enterprise App Development (very similar to Web Dev). Another

One possibility might be DevOps Engineering (System and/or Network). Another possibility might be Enterprise App Development (very similar to Web Dev). Another possibility could relate to Virtualization (OpenStack was built with Python for example). I'm not sure about freelancing in an Enterprise Environment, but a consulting style of approach should work great. I come from a System and Network Engineering Background but I also do Django/Python Web Development. I've been fortunate in that many of my Engineering related side-projects relate to Python in one way or another. So I've been able to re-use what I've learned in many different verticals (currently focused on Security and Virtualization)