I don't think the value of senior developers is so much in knowing how more things work, but rather that they've learnt (over many projects of increasing comple

I don't think the value of senior developers is so much in knowing how more things work, but rather that they've learnt (over many projects of increasing complexity) how to design and build larger more complex systems, and this knowledge mostly isn't documented for LLMs to learn from. An LLM can do the LLM thing and copy designs it has seen, but this is cargo-cult behavior - copy the surface form of something without understanding why it was built that way, and when a different design would have been better for a myriad of reasons. This is really an issue for all jobs, not just software development, where there is a large planning and reasoning component. Most of the artifacts available to train an LLM on are the end result of reasoning, not the reasoning process themselves (the day by day, hour by hour, diary of the thought process of someone exercising their journeyman skills). As far as software is concerned, even the end result of reasoning is going to have very limited availability when it comes to large projects since there are relatively few large projects that are open source (things like Linux, gcc, etc). Most large software projects are commercial and proprietary. This is really one of the major weaknesses of LLM-as-AGI, or LLM-as-human-worker-replacement - their lack of ability to learn on the job and pick up a skill for themselves as opposed to needing to have been pre-trained on it (with the corresponding need for training data). In-context learning is ephemeral and anyways no substitute for weight updates where new knowledge and capabilities have been integrated with existing knowledge into a consistent whole.