I'm trying to understand how using django for development works. Can a backend developer begin with just a wireframe? Isn't it possible to develop scripts while someone else is writing the html/css code? (like working on the front end and back end at the same time)
For example: Creating a forum. Can't the backend develop the features like creating a community, managing the community and storing the information in the DB and then once the integration begins, take the html/css and combine it?
Yes of course they can. Django uses a templating system that makes it very easy to drop in html and css after or while the backend is being developed. The backend views just need to pass the data to the template (regardless of whether or not it exists yet) and the templates can be modified to use the actual data. Obviously, there are some limits to this (for instance, if users need to submit forms, the backend can't test their views until the forms exist), but in general, this is a widely accepted way of developing.