Excel performance: Tips for optimizing performance obstructions

https://docs.microsoft.com/en-us/office/vba/excel/concepts/excel-performance/excel-tips-for-optimizing-performance-obstructions

Excel Full Column References and Used Range: Good Idea or Bad Idea?

https://docs.microsoft.com/en-us/office/vba/excel/concepts/excel-performance/excel-tips-for-optimizing-performance-obstructions