diff --git a/.travis.yml b/.travis.yml
index 728ef56cd05..67044b9485a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -72,7 +72,7 @@ script:
   - |
     bash -c "
       if [ '$RUN_LINT' == '1' ]; then
-        bundle exec rubocop --parallel && \
+        bundle exec danger && \
         eslint --ext .es6 app/assets/javascripts && \
         eslint --ext .es6 test/javascripts && \
         eslint --ext .es6 plugins/**/assets/javascripts && \
diff --git a/Dangerfile b/Dangerfile
new file mode 100644
index 00000000000..a3934b51a7d
--- /dev/null
+++ b/Dangerfile
@@ -0,0 +1,29 @@
+require 'json'
+
+if git.lines_of_code > 500
+  warn("This PR seems big, we prefer smaller PR. Please be sure this is needed and can’t be split in smaller commits.")
+end
+
+rubocop_output = `bundle exec rubocop --parallel`
+if !rubocop_output.empty?
+  offenses = JSON.parse(rubocop_output)['files']
+    .select { |f| f['offenses'].any? }
+
+  fail(%{
+    This PR has multiple rubocop offenses:
+
+    #{offenses.join("\n")}
+  })
+end
+
+prettier_output = `prettier --list-different "app/assets/stylesheets/**/*.scss" "app/assets/javascripts/**/*.es6" "test/javascripts/**/*.es6" "plugins/**/*.scss" "plugins/**/*.es6"`
+if !prettier_output.empty?
+  offenses = JSON.parse(prettier_output)['files']
+    .select { |f| f['offenses'].any? }
+
+  fail(%{
+    This PR has multiple prettier offenses:
+
+    #{offenses.join("\n")}
+  })
+end
diff --git a/Gemfile b/Gemfile
index 95e20d4cf65..3ec355c0a8f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -108,6 +108,7 @@ group :test do
   gem 'webmock', require: false
   gem 'fakeweb', '~> 1.3.0', require: false
   gem 'minitest', require: false
+  gem 'danger'
 end
 
 group :test, :development do
diff --git a/Gemfile.lock b/Gemfile.lock
index dc24ed1b27f..2118599739d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -76,13 +76,33 @@ GEM
     byebug (10.0.2)
     certified (1.0.0)
     chunky_png (1.3.10)
+    claide (1.0.2)
+    claide-plugins (0.9.2)
+      cork
+      nap
+      open4 (~> 1.3)
     coderay (1.1.2)
+    colored2 (3.1.2)
     concurrent-ruby (1.0.5)
     connection_pool (2.2.2)
+    cork (0.3.0)
+      colored2 (~> 3.1)
     cppjieba_rb (0.3.0)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
     crass (1.0.4)
+    danger (5.6.3)
+      claide (~> 1.0)
+      claide-plugins (>= 0.9.2)
+      colored2 (~> 3.1)
+      cork (~> 0.1)
+      faraday (~> 0.9)
+      faraday-http-cache (~> 1.0)
+      git (~> 1)
+      kramdown (~> 1.5)
+      no_proxy_fix
+      octokit (~> 4.7)
+      terminal-table (~> 1)
     debug_inspector (0.0.3)
     diff-lcs (1.3)
     discourse_image_optim (0.26.2)
@@ -113,6 +133,8 @@ GEM
     fakeweb (1.3.0)
     faraday (0.12.2)
       multipart-post (>= 1.2, < 3)
+    faraday-http-cache (1.3.1)
+      faraday (~> 0.8)
     fast_blank (1.0.0)
     fast_xor (1.1.3)
       rake
@@ -125,6 +147,7 @@ GEM
       thor (~> 0.19.1)
     fspath (3.1.0)
     gc_tracer (1.5.1)
+    git (1.4.0)
     globalid (0.4.1)
       activesupport (>= 4.2.0)
     guess_html_encoding (0.0.11)
@@ -147,6 +170,7 @@ GEM
       thor (>= 0.14, < 2.0)
     jwt (1.5.6)
     kgio (2.11.2)
+    kramdown (1.17.0)
     libv8 (6.7.288.46.1)
     listen (3.1.5)
       rb-fsevent (~> 0.9, >= 0.9.4)
@@ -189,6 +213,8 @@ GEM
     multi_xml (0.6.0)
     multipart-post (2.0.0)
     mustache (1.0.5)
+    nap (1.1.0)
+    no_proxy_fix (0.1.2)
     nokogiri (1.8.3)
       mini_portile2 (~> 2.3.0)
     nokogumbo (1.5.0)
@@ -200,6 +226,8 @@ GEM
       multi_json (~> 1.3)
       multi_xml (~> 0.5)
       rack (>= 1.2, < 3)
+    octokit (4.9.0)
+      sawyer (~> 0.8.0, >= 0.5.3)
     oj (3.6.2)
     omniauth (1.8.1)
       hashie (>= 3.4.6, < 3.6.0)
@@ -235,6 +263,7 @@ GEM
       mustache
       nokogiri (~> 1.7)
       sanitize
+    open4 (1.3.4)
     openid-redis-store (0.0.2)
       redis
       ruby-openid
@@ -354,6 +383,9 @@ GEM
       bundler
       ffi (~> 1.9.6)
       sass (>= 3.3.0)
+    sawyer (0.8.1)
+      addressable (>= 2.3.5, < 2.6)
+      faraday (~> 0.8, < 1.0)
     seed-fu (2.3.9)
       activerecord (>= 3.1)
       activesupport (>= 3.1)
@@ -378,6 +410,8 @@ GEM
       sprockets (>= 3.0.0)
     sshkey (1.9.0)
     stackprof (0.2.11)
+    terminal-table (1.8.0)
+      unicode-display_width (~> 1.1, >= 1.1.1)
     thor (0.19.4)
     thread_safe (0.3.6)
     tilt (2.0.8)
@@ -423,6 +457,7 @@ DEPENDENCIES
   byebug
   certified
   cppjieba_rb
+  danger
   discourse_image_optim
   email_reply_trimmer (~> 0.1)
   ember-handlebars-template (= 0.7.5)