It seems so obvious now, but it does make me thankful that my training drilled into my head to constantly ask "what is the problem I am trying to solve?". Communication in a team on what's going on (both in your head and the overall problem space) is just as important as the mechanical process of coding it.
I feel that's the bare minimum a junior should be asking. the "this is useful" or "this is slop" will come with experience, but you need to at least be able to explain what's going on.
the transition to mid and senior goes when you can start to quantify other aspects of the code. Like performance, how widespread a change affects the codebase at large, the input/outputs expected, and the overall correctness based on the language. Balancing those parameters and using it to accurately estimate a project scope is when you're really thinking like a senior.
I do think that there's a meaningful difference between writing code that was bad (which I definitely did and do) and writing code where I didn't know what each line did.
early on when I was doing iOS development I learned that "m34" was the magic trick to make flipping a view around have a nice perspective effect, and I didn't know what "m34" actually meant but I definitely knew what the effect of the line of code that mutated it was...
Googling on it now seems like a common experience for early iOS developers :)
Senior level. Still can't sometimes. Just the other day I looked over some code I wrote and realized what a pile of slop it was. I kept wondering "What was I thinking when I wrote this? And why couldn't I see how bad it is till now?" My impostor syndrome is triggered hard now.
