This is exactly right. Judgement is what coders really need. Does this thing look like an n^2 algorithm? Let's fix it. Does this thing look like something that someone else has likely come across before? Let's see what they did.

You cover a lot of ground as a coder having skimmed an algorithm book. So I do actually think there's some value in DSA preparation. At the same time I'll admit I don't have any of those things memorized, I just know they are things and can pattern match aka learn when they show up.

You realize the difference when you run into an inexperienced coder, especially a smart person like a quant. They run into a problem and think it's new, and solve it naively.