Add some memory caching for now

app/controllers/api/v1/cards_controller.rb

@@ -1,10 +1,12 @@
 class Api::V1::CardsController < Api::V1::BaseController
   before_action :set_card, only: [:show]
   def index
-    @cards = Card.includes(:character, :rarity, :type, :leader_skill,
-                           :passive_skill, :super_attack, :awaken_type,
-                           :dokkan_card, :hp_stat, :atk_stat, :def_stat,
-                           :links)
+    @cards = Rails.cache.fetch('api_all_cards', expires_in: 2.minutes) do
+      Card.includes(:character, :rarity, :type, :leader_skill,
+                    :passive_skill, :super_attack, :awaken_type,
+                    :dokkan_card, :hp_stat, :atk_stat, :def_stat,
+                    :links)
+    end
 
     render json: @cards, root: false
   end

config/environments/production.rb

@@ -13,6 +13,7 @@ Rails.application.configure do
   # Full error reports are disabled and caching is turned on.
   config.consider_all_requests_local       = false
   config.action_controller.perform_caching = true
+  config.cache_store = :memory_store
 
   # Enable Rack::Cache to put a simple HTTP cache in front of your application
   # Add `rack-cache` to your Gemfile before enabling this.