In this article, Andreas Grabner analyzes the performance implication of using the SharePoint Object Model, specifically displaying and editing lists, one of the most used SharePoint objects.
Read: SharePoint Object Model Performance Considerations
The article focuses on SharePoint lists. There are many list usage approaches described by the SharePoint documentation, but not all are recommended for any scenario. Grabner advices the readers on how to avoid the performance pitfalls associated to improper use of lists by giving problematic code samples and their corresponding recommended ones.