Those handle a lot of the simple use cases and some of the complex ones. They have the virtue of being well-tested and integrated with your development platform. You can deploy in one step and maintain one database. Which is great till it isn't.
What platform libraries like Devise, etc, don't offer is user data denormalization and isolation, which is useful when you have 2 or more applications with users. Then you want to look at auth servers (self-hosted or SaaS).
But you want the auth server experience to be as simple as possible, which is what we're working towards.
Those handle a lot of the simple use cases and some of the complex ones. They have the virtue of being well-tested and integrated with your development platform. You can deploy in one step and maintain one database. Which is great till it isn't.
What platform libraries like Devise, etc, don't offer is user data denormalization and isolation, which is useful when you have 2 or more applications with users. Then you want to look at auth servers (self-hosted or SaaS).
But you want the auth server experience to be as simple as possible, which is what we're working towards.
My two cents.