One of the most important parts of the development cycle here at Microsoft is the time we spend tuning the performance of our products.
Performance tuning is something that developers see as a critical part of checking in a feature.
The example that I'll tune today is a table-building program. Each row contains a single cell. I started off with a chunk of code that I thought would be fast. All the pages are loaded from a local drive. There is only one other reference to this property, so this change should be pretty minor.