This is actually a real case in my product with is currently a knowledge base around 100K people using it daily. The permission is very flexible(due to the inherit permission), and we spent so much effort on optimizing the loading speed. Until I saw Zanzibar and realized that we was not even speaking the permission domain language in our system. I like spicedb a lot, it's simple and very expressive. So I'm thinking if I can adopt it in my product😀