diff --git a/ruby/gilded_rose.rb b/ruby/gilded_rose.rb
index e177a497..230d0a3b 100644
--- a/ruby/gilded_rose.rb
+++ b/ruby/gilded_rose.rb
@@ -1,56 +1,48 @@
 class GildedRose
-
   def initialize(items)
     @items = items
   end
 
-  def update_quality()
+  def update_quality
     @items.each do |item|
-      if item.name != "Aged Brie" and item.name != "Backstage passes to a TAFKAL80ETC concert"
-        if item.quality > 0
-          if item.name != "Sulfuras, Hand of Ragnaros"
-            item.quality = item.quality - 1
-          end
-        end
-      else
-        if item.quality < 50
-          item.quality = item.quality + 1
-          if item.name == "Backstage passes to a TAFKAL80ETC concert"
-            if item.sell_in < 11
-              if item.quality < 50
-                item.quality = item.quality + 1
-              end
-            end
-            if item.sell_in < 6
-              if item.quality < 50
-                item.quality = item.quality + 1
-              end
-            end
-          end
-        end
-      end
-      if item.name != "Sulfuras, Hand of Ragnaros"
-        item.sell_in = item.sell_in - 1
-      end
-      if item.sell_in < 0
-        if item.name != "Aged Brie"
-          if item.name != "Backstage passes to a TAFKAL80ETC concert"
-            if item.quality > 0
-              if item.name != "Sulfuras, Hand of Ragnaros"
-                item.quality = item.quality - 1
-              end
-            end
-          else
-            item.quality = item.quality - item.quality
-          end
-        else
-          if item.quality < 50
-            item.quality = item.quality + 1
-          end
-        end
-      end
+      # Skip updating 'Sulfuras' items, as they have fixed quality and do not degrade
+      next if item.name == 'Sulfuras, Hand of Ragnaros'
+
+      # Update item quality based on item type
+      item.quality = case item.name
+                     when 'Aged Brie'
+                       [50, item.quality + update_count(item)].min
+                     when 'Backstage passes to a TAFKAL80ETC concert'
+                       backstage_passes(item)
+                     when 'Conjured Mana Cake'
+                       [0, item.quality - update_count(item) * 2].max
+                     else
+                       [0, item.quality - update_count(item)].max
+                     end
+
+      item.sell_in -= 1
     end
   end
+
+  private
+
+  # Helper method to determine the update count based on sell_in
+  def update_count(item)
+    (item.sell_in.negative? ? 2 : 1)
+  end
+
+  # Helper method to handle 'Backstage passes' quality update
+  def backstage_passes(item)
+    return 0 if item.sell_in.negative?
+
+    if item.sell_in <= 5
+      [50, item.quality + 3]
+    elsif item.sell_in <= 10
+      [50, item.quality + 2]
+    else
+      [50, item.quality + 1]
+    end.min
+  end
 end
 
 class Item
diff --git a/ruby/gilded_rose_spec.rb b/ruby/gilded_rose_spec.rb
index 015a759f..dade83dc 100644
--- a/ruby/gilded_rose_spec.rb
+++ b/ruby/gilded_rose_spec.rb
@@ -1,11 +1,85 @@
 require 'rspec'
-
 require File.join(File.dirname(__FILE__), 'gilded_rose')
 
 describe GildedRose do
-  it "does not change the name" do
-    items = [Item.new("foo", 0, 0)]
-    GildedRose.new(items).update_quality()
-    expect(items[0].name).to eq "fixme"
+  it 'does not change the name' do
+    items = [Item.new('foo', 0, 0)]
+    GildedRose.new(items).update_quality
+    expect(items[0].name).to eq 'foo'
+  end
+
+  let(:items) do
+    [
+      Item.new('Aged Brie', 2, 0),
+      Item.new('Elixir of the Mongoose', 5, 7),
+      Item.new('Sulfuras, Hand of Ragnaros', 0, 80),
+      Item.new('Backstage passes to a TAFKAL80ETC concert', 15, 20),
+      Item.new('Conjured Mana Cake', 3, 6),
+      Item.new('Apple Furit', 10, 20)
+    ]
+  end
+
+  let(:rose) do
+    GildedRose.new(items)
+  end
+
+  let('after_1_day_item') do
+    {
+      'Aged Brie' => [1, 1],
+      'Elixir of the Mongoose' => [4, 6],
+      'Sulfuras, Hand of Ragnaros' => [0, 80],
+      'Backstage passes to a TAFKAL80ETC concert' => [14, 21],
+      'Conjured Mana Cake' => [2, 4],
+      'Apple Furit' => [9, 19]
+    }
+  end
+
+  it 'test after 1 day' do
+    rose.update_quality
+
+    items.each do |item|
+      expect(item.sell_in).to eq after_1_day_item[item.name][0]
+      expect(item.quality).to eq after_1_day_item[item.name][1]
+    end
+  end
+
+  let('after_2_day_item') do
+    {
+      'Aged Brie' => [0, 2],
+      'Elixir of the Mongoose' => [3, 5],
+      'Sulfuras, Hand of Ragnaros' => [0, 80],
+      'Backstage passes to a TAFKAL80ETC concert' => [13, 22],
+      'Conjured Mana Cake' => [1, 2],
+      'Apple Furit' => [8, 18]
+    }
+  end
+
+  it 'test after 2 day' do
+    rose.update_quality
+
+    items.each do |item|
+      expect(item.sell_in).to eq after_1_day_item[item.name][0]
+      expect(item.quality).to eq after_1_day_item[item.name][1]
+    end
+  end
+
+  let('after_3_day_item') do
+    {
+      'Aged Brie' => [-1, 4],
+      'Elixir of the Mongoose' => [2, 4],
+      'Sulfuras, Hand of Ragnaros' => [0, 80],
+      'Backstage passes to a TAFKAL80ETC concert' => [12, 23],
+      'Conjured Mana Cake' => [0, 0],
+      'Apple Furit' => [7, 17]
+    }
+  end
+
+  it 'test after 3 day' do
+    rose.update_quality
+
+    items.each do |item|
+      expect(item.sell_in).to eq after_1_day_item[item.name][0]
+      expect(item.quality).to eq after_1_day_item[item.name][1]
+    end
   end
 end