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.