What is the best way to implement authorization for a large project?

Question

Ruby on Rails

Hello. What is the best way to implement authorization for a future scalable project? Write by hand or use some kind of gem? With devise already suffered when trying to customize.
Here's what you need:
1. Basic registration.
2. Authorization by email and password.
3. Password recovery by email.
4. Editable user profile.

Answer 1

Devise is very easy to customize. Never really had a problem with it. And it is displayed in a modal window, and Ajax authorization is easily done, and authorization through mobile applications is painless.
Maybe before reinventing the wheel you can say what exactly you can’t customize?

Answer 2

Write your own, I don’t see anything extraordinary, cut api right away.
If it is highly scalable, then it actually does not hurt to immediately put into it a semblance of a separate service for authorization in all components.
In general, the similarity of what we now have on Habré, etc. -TM.id