I would argue that many engineering “best practices” have become much more important much earlier in projects. Personally, I can deal with a lot of jank and lack of documentation in a early stage codebase, but LLMs get lost so quickly, or they just multiply the jank faster than anyone ever could have in the past, making it much, much worse for both LLMs and humans.

Documentation, variable naming, automated tests, specs, type checks, linting. Anything the agent can bang its proverbial head against in a loop for a while without involving you every step of the way.