Rails is a great framework that prevents you from dealing with a lot of boilerplate when it comes to web applications and to focus only on the business logic. T

Rails is a great framework that prevents you from dealing with a lot of boilerplate when it comes to web applications and to focus only on the business logic. There are some great platforms out there (Heroku, for example) that deal with most of the stuff you mentioned (logs, tracing, autoscaling, etc.), and no one prevents you from using a third party service for auth in Rails as well (Auth0, for example). FaaS is awesome, but you've got to code a lot of stuff that Rails gives you for free. Besides, pushing some logic down to infrastructure locks you in the provider you chose. I'm not saying that's bad, because as I've mentioned before I run some apps fully Serverless in AWS, but there's some stuff you've got to take into consideration.