About the nginx version: - 0.7.65 is the version currently used in ubuntu lucid. We use it only as a proxy. - On services like python-wsgi we currently use 0.

About the nginx version: - 0.7.65 is the version currently used in ubuntu lucid. We use it only as a proxy. - On services like python-wsgi we currently use 0.8.52 and we will soon upgrade to 0.8.54 - On the ruby-passenger service we follow the nginx pulled by passenger So it's always dependent of the context. The idea is to keep the stacks stable and secure at all times. Once we have tested and approved an upgrade we create a new revision of the corresponding service and deploy it across the platform. If the upgrade requires downtime we schedule a rolling maintenance window and notify users. On caching: We don't cache by default (but this could change). Users have the option to add caching services like varnish.