We've had no issues with scalability.

There were no scalability issues at all. Alfresco Enterprise is top notch with its clustering capabilities. Even in smaller installations, the software requires just minor adjustments to server resources and a few configuration changes.

It's been a big selling point of the software for years, and that's easily one of the strongest Alfresco features.

No, Alfresco scales very well in the web, application, and database layers. A typical high availability installation would consist of Apache web servers in the DMZ as SSL terminators, caching of static content, URL rewrite, and load-balancing between the nodes in the Alfresco server cluster, which can be scaled separately to the web layer and the database layer. The database layer can also be scaled separately via MySQL Master-Slave or for example PostgreSQL XtraDB cluster. The meta-data (database files) and content (content files and index) is typically stored on a SAN (such as a NetApp), making it easy to support a DR scenario. You provision application files and configuration via Puppet and content files, index, and database files are managed by the SAN.

We did not experience any scalability issues. We are actually following the Alfresco guide for the required resources.

We did not encounter any scalability issues; only some minor improvements are needed.

The product uses state-of-the-art J2EE frameworks and libraries.