For a food bank charity we put together a complex plan for a WordPress multisite containing:

at least 3 different but connected themes
a shared media system
a process for pushing content from subsite to the “main” site without db headache
a live clone system
all of these and more helped us keep the charity and their over 400 locations all have a web presence. This talk will cover the ups and downs of this complex behemoth and the lessons we learnt from it.