There's a difference between "can generate" and "can create [from scratch]". Of course LLMs can generate code that reflects common patterns in the stuff it was trained, such as frontend/backend splits, since this is precisely what they are trained to be able to do.

Coming up with a new design from scratch, designing (or understanding) a high level architecture based on some principled reasoning, rather than cargo cult coding by mimicking common patterns in the training data, is a different matter.

LLMs are getting much better at reasoning/planning (or at least something that looks like it), especially for programming & math, but this is still based on pre-training, mostly RL, and what they learn obviously depends on what they are trained on. If you wanted LLMs to learn principles of software architecture and abstraction/etc, then you would need to train on human (or synthetic) "reasoning traces" of how humans make those decisions, but it seems that currently RL-training for programming is mostly based on artifacts of reasoning (i.e. code), not the reasoning traces themselves that went into designing that code, so this (coding vs design reasoning) is what they learn.

I would guess that companies like Anthropic are trying to address this paucity of "reasoning traces" for program design, perhaps via synthetic data, since this is not something that occurs much in the wild, especially as you move up the scale of complexity from small problems (student assignments, stack overflow advice) to large systems (which are anyways mostly commercial, hence private). You can find a smallish number of open source large projects like gcc, linux, but what is missing are the reasoning traces of how the designers went from requirements to designing these systems the way they did (sometimes in questionable fashion!).

Humans of course learn software architecture in a much different way. As with anything, you can read any number of books, attend any number of lectures, on design principles and software patterns, but developing the skill for yourself requires hands-on personal practice. There is a fundamental difference between memory (of what you read/etc) and acquired skill, both in level of detail and fundamental nature (skills being based on action selection, not just declarative recall).

The way a human senior developer/systems architect acquires the skill of design is by practice, by a career of progressively more complex projects, successes and failures/difficulties, and learning from the process. By learning from your own experience you are of course privy to your own prior "reasoning traces" and will learn which of those lead to good or bad outcomes. Of course learning anything "on the job" requires continual learning, and things like curiosity and autonomy, which LLMs/AI do not yet have.

Yes, us senior meatbags, will eventually be having to compete with, or be displaced by, machines that are the equal of us (which is how I would define AGI), but we're not there yet, and I'd predict it's at least 10-20 years out, not least because it seems most of the AI companies are still LLM-pilled and are trying to cash in on the low-hanging fruit.

Software design and development is a strange endeavor since, as we have learnt, one of the big lessons of LLMs (in general, not just apropos coding), is how much of what we do is (trigger alert) parroting to one degree or another, rather than green field reasoning and exploration. At the same time, software development, as one gets away from boilerplate solutions to larger custom systems, is probably one of the more complex and reasoning-intensive things that humans do, and therefore may end up being one of the last, rather than first, to completely fall to AI. It may well be AI managers, not humans, who finally say that at last AI has reached human parity at software design, able to design systems of arbitrary complexity based on principled reasoning and accumulated experience.