It's funny how we drill the idea that everything must be reimplemented from first principles into students, only to flip that when they join the workforce.
When doing things for real in the workforce, reinventing core parts yourself is often not the best way, if only because you'll reinvent already fixed bugs too or that it wastes time, and that should be explained too. But understanding how things work below the outer layer of what would otherwise be black boxes lets you better understand when things go wrong, or have a better position to assess a pre-made library/service/other to be confident it is the most suitable option¹. Also, building things from scratch helps teach complexity analysis and, at a slightly higher level, security analysis, both of which are very useful, often vital, at much higher and/or more abstract levels.
If building from first principles, or close to, is being drilled into students as the way to do things full stop, then those students are being taught poorly. It isn't how I remember learning way back when I was last called a student.
For example my understanding of how b-trees and their relatives work, in part from having build routines to manage them in the dim and distant past, along with a number of other similar bits of knowledge, helps my understanding of how many DBMSs work in general and how certain optimisations at higher levels² do/don't work. I doubt I'll ever need to build any structure like that from anything close to first principles, but having done so in the past was not wasted time. The same with knowledge of filesystem construction, network protocols, etc. – I'll probably not use those things directly but the understanding helps me make choices, create solutions³, and solve problems, less directly.
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[1] or at least a suitable option
[2] things I do in the query syntax, what the query planner/runner can/can't do with that, etc.
[3] I am sometimes the local master of temporary hacky solutions that get us over the line and allow time to do things more right slightly later instead of things failing right now.
Kind of makes sense, doesn't it? While in school, you want to learn as much as possible (ideally?), while in the workforce, you want (or the company wants you) to be as efficient as possible. Different goals leads to different workflows.
I think the same connection can be made to StackOverflow. If you are/were a computer science student and you did a lot of copy-pasting and not a lot of thinking and trialing, there's a really good change you didn't get to suffer mistakes during development that you know to avoid now as a graduate. Now, we all have taken advantage of code from StackOverflow and that's a tool to aid development for us, but when it's something you treat as a crutch, when it doesn't have the answers you need, you're screwed.
One case I saw literally yesterday at work. We had a dev that had written a lot of copy-pasted code saying that it couldn't be generalized and take advantage of a mapping we already have to generate a UI. This dev had not yet had the fortune of learning how to properly abstract this kind of problem in this specific circumstance. I sat down with him for a moment and instead of spitting out a bunch of nonsense that the LLM was trying to get him to write, we say down and paired on the issue until we had a more general solution.
He learned some abstraction concepts, we all got a better code base, and he learned a way to help tease an LLM into a better solution going forward. That foundation was required to get that better solution though, in this situation.
Generally speaking, I think you should know all your underlying concepts so you can audit any new development assisting tools.
A surprisingly large number of people do not realise that code on StackOverflow is under a relatively restrictive license.
https://meta.stackexchange.com/questions/12527/do-i-have-to-...
Some companies take this very seriously and others do not care at all. And, of course, there are companies that outright ban any library without the right licence.
"return a + b": plagiarism, disqualified.
"return a + 1 + b - 1": A+
It is funny, but that doesn’t mean it’s wrong.
PS If the domain in your profile is supposed to be valid … it isn’t.
Thanks, I need to redo my website/blog/whatever. I'm still getting email at it!
Where on earth did you go to school that you couldn't just call list.sort() after your first algorithms class? I've never seen a class that teaches students that everything must be implemented from first principles. They only do that for the concepts taught in that class, or 1-2 classes prior, to make sure you are actually learning and have a clue what you're doing. Which... should makes sense? You should want engineers to cut costs based on understanding rather than ignorance.