Code for blog post "ActiveAdmin: Redirect to Index on Create/Update" - http://nomethoderror.com/blog/2014/03/10/activeadmin-redirect-to-index-on-create-update/

resource.rb

ActiveAdmin.register User do
  
  # ...truncated code...
  
  controller do
    def create
      super do |format|
        redirect_to collection_url and return if resource.valid?
      end
    end

    def update
      super do |format|
        redirect_to collection_url and return if resource.valid?
      end
    end
  end

end