I'll be honest I don't have much experience with Redis specifically, I do however think that the caching layer is likely the wrong place to handle data security

I'll be honest I don't have much experience with Redis specifically, I do however think that the caching layer is likely the wrong place to handle data security. It seems too easy for someone to accidentally circumvent the cache and thereby the security. I do think that organising the cache to catch problems early is a good idea though. The thing is that a function like def get_profile(user_id): profile = fetch_profile(user_id) assert profile.user_id == user_id return user_id makes it a lot harder to fuck up, doesn't matter if you swap some ids somewhere (i.e. fetch_profile actually uses the customer id, not the user_id), or if the cache fucks up, or if you accidentally wrote 'SELECT * FROM user_profile WHERE user_id = user_id'.