Yesterday Wil Clouser wrote up a blog post detailing infrastructure changes for addons.mozilla.org in 2010.

Notable changes are:

• Migrating from CakePHP to Django
• Moving from SVN to Git
• Continuous integration
• Faster deployment
• Processing data offline
• Improved documentation

Take a look, it’s a good overview of the technical challenges of managing a large and complex website at an enormous scale.