I'm coming from Java world where stateless-service-based systems are popular.
In Ruby world it is not so popular and I can't find any answer, how to do that.

Say I need CRUD service to store Orders. It is pure stateless, no instance variables, just methods like `create`, `read`, etc. I wonder if I should create new instance of it every time I want to use it? In java with Spring or Guice you have one instance that may be used concurrently. 

I can think of the following ways to implement that

1) regular class, and call `OrderRepository.new` every time 

```
  class OrderRepository
    def create(order)
       ..
    end
  end

```

2) class methods and call `OrderRepository.create` (doesn't sound good)

```
  class OrderRepository
    def self.create(order)
       ..
    end
  end

```

3) module instead of class

Which one is preferable in such case?