> How do you think engineers in the second half got there? By writing tons and tons of code to "build those reps" and gain that experience.

Well this is true, but that doesn't mean that there isn't any other way to acquire this knowledge. Until now, this way of gaining deeper understanding was simply the most practical one, since you needed to write lots of code when starting out as a software engineer.

But it's just as well possible to gain knowledge about useful abstractions and clean code by using AI to do the work. You'll find out after a while which codebases get you stuck and which code abstractions leverage your AI because it needs fewer tokens to read and extend your codebase.