That largely depends on your existing architecture. Some of us have authorizations services, others have a separate database to store policies and others have authorization rules deep into their existing code base.
However, as I mention in the post, Hasura is great if you make the decision to use it early for a project, but it's not a luxury everyone has, and not a decision everyone will want to make even starting a new project.
> because it's not just about creating the right query to fetch data optimally, but it is also about making sure that it's handling data with the right authorization context of the current end-user.
You're absolutely right that its tricky. (A good example of this is Facebook building a viewer-aware entity layer for some of these reasons). Hasura makes this great as well, but again, many are not in a position so "simply use Hasura". That's why I quickly mention that the post will focus on existing/mature/complex codebases.