> focus on is how to make it not slow That's the same thing, worded differently. A junior programmer might focus on looping for-loops backwards "for speed" and

> focus on is how to make it not slow That's the same thing, worded differently. A junior programmer might focus on looping for-loops backwards "for speed" and then leave a serial `await` in the loop itself. If you don't see that that's a problem, no "focus" will help.