"Flattening", the equivalent of denormalizing a graph, is one way to implement performant ACL Filtering[0]. This is the same strategy used in the Zanzibar paper

"Flattening", the equivalent of denormalizing a graph, is one way to implement performant ACL Filtering[0]. This is the same strategy used in the Zanzibar paper to gain the desired performance out of their Leopard index system. I tend to consider this largely a performance optimization strategy and not a necessarily the "solution" to this problem. We actually just this week wrote about how Authzed[1] actually reverse walks the graph in order to implement this API. Full disclosure: I'm a founder of Authzed (YC W21), which is a productized Zanzibar system. [0]: https://authzed.com/blog/six-month-profile-page/ https://authzed.com/blog/six-month-profile-page/ [1]: https://authzed.com/blog/acl-filtering-in-authzed/ https://authzed.com/blog/acl-filtering-in-authzed/