Actually I think you're misunderstanding me. I'm not saying you should profile and optimize all the code you write, I'm saying that a basic understanding of alg

Actually I think you're misunderstanding me. I'm not saying you should profile and optimize all the code you write, I'm saying that a basic understanding of algorithms, data structures and complexity analysis allows you to write better code without any extra tools. I didn't profile this report to find out why it took 30+ minutes to run. I just happened across some code, read it, saw that it was essentially two nested loops iterating through two huge (50-80k elements each) lists matching items by name, changed it to use a dictionary instead of the inner loop and that was that. It's a trivial change, it wouldn't have taken any longer to write this the first time around. There is no excuse for doing this, it's just a dev who doesn't understand what they're doing. That's my point. Understanding these fundamentals allows you to avoid these types of pitfalls and understand when it's okay to write something inefficient and when it isn't.