Zuckerberg has no clue about software development. He always wants young people, huge bullpen offices, moonshot projects like the Metaverse that fail.

Facebook open source software does not have great code quality. In some projects that always have been a huge mess they are now adding claude.md files to guide their beloved "AI". They did not add these files for humans before.

I think Facebook software is a lost case where it does not matter if you perform the weekly rewriting by LLM or by kLOC driven humans.