Abhilash Raj writes:

What you need to start with is clearly stating what do you mean by "Dashboard",

+1

Also (I've referenced this before), two years ago Systers had a project "Mailman Interface" or "MI" which was exactly a dashboard (if by dashboard you mean a "collection of widgets nicely arranged to manage various aspects of your Mailman activities and configuration"). The student was Shanu Salunke aka dardie, I think her stuff was on github under dardie.