CPU Profiles

An order export starts to take too long. An engineer reads the code, decides that the tax arithmetic in Total must be the slow part, and spends an afternoon making it cleverer. The export takes exactly as long as it did before.

A benchmark would have shown that Total is slow, but it would not have shown which part of Total is responsible. In the program measured on this page, the tax calculation takes so little time that it receives almost no samples.