For simple work, sometimes you can only optimize a little, let alone - 10x. For advanced stuff, the difference is not 10x. It is infinite. Some people would do

For simple work, sometimes you can only optimize a little, let alone - 10x. For advanced stuff, the difference is not 10x. It is infinite. Some people would do it well, some poorly, and order(s) of magnitude longer, most - not at all, even if they put decades into that. Think: how long would a regular software developer take to do John Carmack's work on Wolfenstein and Doom?