Ask HN: How do you split work on web apps?

About a year ago at my workplace we decided to get into developing a web app for internal use (as part of a more intricate system which is irrelevant to this question). No one really had experience in web development, so probably some of our decisions were wrong, but all in all we've had success with the tool we were developing. Since we did have experience developing in Python, we chose Django as our platform.

My question is about "who does what". The way we split our work was: there is one team which handles all the Python code - which means all the Django urls, views and models, as well as the actual backend to handle asynchronous task execution (something a bit like Celery). A different team (more precisely, a single person in a different development group - but this is just implementation) is responsible for the templates (data binding), javascript, design, HTML, CSS, etc.

We have been working like this, as I said, for about a year now. I'm starting to think that maybe the line of responsibilities between the two teams is wrong. The reason is that there's a pretty big overhead whenever we need to interact - which is a lot. For example, when we add a new table and we want to display it, we need to let the "frontend guy" know what the url would be and what it would contain. Then we need to integrate out work to see if everything's alright. Sometimes we didn't pass enough context to the template to make it work and there's a slow ping-pong of information between us.

So my question is this - what is the accustomed way to split work on web apps? Who takes care of the different modules - models, views, urls, templates, design, user experience, HTML, CSS, javascript? I'd love to know how YOU do it.