1) The document discusses 7 common mistakes made when building scalable SharePoint applications. The first mistake is conflating performance and scalability, where an application may perform well for one user but not scale to support thousands of concurrent users. 2) The second mistake is using SharePoint lists as an OLTP database, as lists are not optimized for transactional data. It is better to use a custom SQL database and connect to SharePoint using provider hosted apps. 3) The seventh and final mistake discussed is failing to leverage Search, as Search provides scalable functionality for indexed data but may not be suitable for all scenarios due to indexing times.