What a neat thing to see crop up on hackernews. I did a mini report on guédelon in one of my French courses in Uni. The name immediately threw me back to memories of trying to describe some of the ‘technical’ aspects of the project in my shoddy early French, haha.
theres a great documentary (or 2) about it, which coincidentally is online for every German and French via arte (but only today but will probably be available again in a few months):
https://www.arte.tv/de/videos/082723-000-A/guedelon-ii/