Most of the LLM prompting skills I figured out ~three years ago are still useful to me today. Even the ones that I've dropped are useful because I know that things that used to be helpful aren't helpful any more, which helps me build an intuition for how the models have improved over time.

Many people figured it out two-three years ago when AI-assisted coding basically wasn't a thing, and it's still relevant and will stay relevant. These are fundamental principles, all big models work similarly, not just transformers and not just LLMs.

However, many fundamental phenomena are missing from the "context engineering" scope, so neither context engineering nor prompt engineering are useful terms.

What exactly month-long AI skills of 2023 AI are obsolete now?

Surely not prompt engineering itself, for example.

If you're not writing your own agents, you can skip this skill.