What authentication and authorization service do you use for microservice architecture?

Question

User identification

Recommend a service for user authentication and authorization. A Google search yielded the following solutions:

• Saas: Auth0 and Okta - not suitable because you don't want to depend on them
  
• Open source - FusionAuth, Keycloak, Gluu, Keratin - it is not known how ready they are for use in production under real load
  
• AWS Cognito - similar, vedndor-lock
  

Do you have experience with any of these services, have you used them on live projects under load?
If you solved a similar problem, where did opensource, saas, your solution stop?

Answer 1

Auth0 is top, but if you need a closed network or no money, then Keycloak. Cognito is only good if the infrastructure is in AWS. I did not like Okta in terms of management and federation at the time when I looked. The rest of these decisions were not even particularly considered.
Depending on the service, as it seems to you, you will not be because they all work on the same protocols. This is just an implementation, and exporting or importing users is not difficult.
I am for Auth0 because I know their architecture. They are psychos, but they did everything very well)