diff --git a/README.md b/README.md
index 28355770..ad7c050b 100644
--- a/README.md
+++ b/README.md
@@ -553,3 +553,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 318. Maximum Product of Word Lengths                            | [Link](https://leetcode.com/problems/maximum-product-of-word-lengths/)                            | [Link](./lib/medium/318_maximum_product_of_word_lengths.rb)                            | [Link](./test/medium/test_318_maximum_product_of_word_lengths.rb)                            |
 | 328. Odd Even Linked List                                       | [Link](https://leetcode.com/problems/odd-even-linked-list/)                                       | [Link](./lib/medium/328_odd_even_linked_list.rb)                                       | [Link](./test/medium/test_328_odd_even_linked_list.rb)                                       |
 | 331. Verify Preorder Serialization of a Binary Tree             | [Link](https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree/)             | [Link](./lib/medium/331_verify_preorder_serialization_of_a_binary_tree.rb)             | [Link](./test/medium/test_331_verify_preorder_serialization_of_a_binary_tree.rb)             |
+| 334. Increasing Triplet Subsequence                             | [Link](https://leetcode.com/problems/increasing-triplet-subsequence/)                             | [Link](./lib/medium/334_increasing_triplet_subsequence.rb)                             | [Link](./test/medium/test_334_increasing_triplet_subsequence.rb)                             |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index 772bc97e..e79221ed 100644
--- a/leetcode-ruby.gemspec
+++ b/leetcode-ruby.gemspec
@@ -5,7 +5,7 @@ require 'English'
 ::Gem::Specification.new do |s|
   s.required_ruby_version = '>= 3.0'
   s.name = 'leetcode-ruby'
-  s.version = '6.8.7'
+  s.version = '6.8.8'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'
diff --git a/lib/medium/334_increasing_triplet_subsequence.rb b/lib/medium/334_increasing_triplet_subsequence.rb
new file mode 100644
index 00000000..a36436c9
--- /dev/null
+++ b/lib/medium/334_increasing_triplet_subsequence.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/increasing-triplet-subsequence/
+# @param {Integer[]} nums
+# @return {Boolean}
+def increasing_triplet(nums)
+  a = ::Float::INFINITY
+  b = ::Float::INFINITY
+
+  nums.each do |num|
+    if num < a
+      a = num
+    elsif num < b && num > a
+      b = num
+    elsif num > a && num > b
+      return true
+    end
+  end
+
+  false
+end
diff --git a/test/medium/test_334_increasing_triplet_subsequence.rb b/test/medium/test_334_increasing_triplet_subsequence.rb
new file mode 100644
index 00000000..2438e416
--- /dev/null
+++ b/test/medium/test_334_increasing_triplet_subsequence.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/334_increasing_triplet_subsequence'
+require 'minitest/autorun'
+
+class IncreasingTripletSubsequenceTest < ::Minitest::Test
+  def test_default_one
+    assert(
+      increasing_triplet(
+        [1, 2, 3, 4, 5]
+      )
+    )
+  end
+
+  def test_default_two
+    assert(
+      !increasing_triplet(
+        [5, 4, 3, 2, 1]
+      )
+    )
+  end
+
+  def test_default_three
+    assert(
+      increasing_triplet(
+        [2, 1, 5, 0, 4, 6]
+      )
+    )
+  end
+end