diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md
index 419911dce6af4..1839372ebe9cb 100644
--- a/railties/CHANGELOG.md
+++ b/railties/CHANGELOG.md
@@ -1,3 +1,20 @@
+*   Added `Railtie#server` hook called when Rails starts a server.
+    This is useful in case your application or a library needs to run
+    another process next to the Rails server. This is quite common in development
+    for instance to run the Webpack or the React server.
+
+    It can be used like this:
+
+    ```ruby
+      class MyRailtie < Rails::Railtie
+        server do
+          WebpackServer.run
+        end
+      end
+    ```
+
+    *Edouard Chin*
+
 *   Remove deprecated `rake dev:cache` tasks.
 
     *Rafael Mendonça França*
@@ -94,7 +111,6 @@
 
     *Eileen M. Uchitelle*, *John Crepezzi*
 
-
 *   Accept params from url to prepopulate the Inbound Emails form in Rails conductor.
 
     *Chris Oliver*
diff --git a/railties/lib/rails/application.rb b/railties/lib/rails/application.rb
index 8738e4b93e130..48b812403b8f9 100644
--- a/railties/lib/rails/application.rb
+++ b/railties/lib/rails/application.rb
@@ -322,6 +322,12 @@ def generators(&blk)
       self.class.generators(&blk)
     end
 
+    # Sends any server called in the instance of a new application up
+    # to the +server+ method defined in Rails::Railtie.
+    def server(&blk)
+      self.class.server(&blk)
+    end
+
     # Sends the +isolate_namespace+ method up to the class method.
     def isolate_namespace(mod)
       self.class.isolate_namespace(mod)
@@ -536,6 +542,11 @@ def run_console_blocks(app) #:nodoc:
       super
     end
 
+    def run_server_blocks(app) #:nodoc:
+      railties.each { |r| r.run_server_blocks(app) }
+      super
+    end
+
     # Returns the ordered railties for this application considering railties_order.
     def ordered_railties #:nodoc:
       @ordered_railties ||= begin
diff --git a/railties/lib/rails/engine.rb b/railties/lib/rails/engine.rb
index 52d1943fea713..ed96b1c8b43d1 100644
--- a/railties/lib/rails/engine.rb
+++ b/railties/lib/rails/engine.rb
@@ -470,6 +470,13 @@ def load_generators(app = self)
       self
     end
 
+    # Invoke the server registered hooks.
+    # Check <tt>Rails::Railtie.server</tt> for more info.
+    def load_server(app = self)
+      run_server_blocks(app)
+      self
+    end
+
     def eager_load!
       # Already done by Zeitwerk::Loader.eager_load_all. We need this guard to
       # easily provide a compatible API for both zeitwerk and classic modes.
diff --git a/railties/lib/rails/generators/rails/app/app_generator.rb b/railties/lib/rails/generators/rails/app/app_generator.rb
index 6c99d54314944..8101d518b3547 100644
--- a/railties/lib/rails/generators/rails/app/app_generator.rb
+++ b/railties/lib/rails/generators/rails/app/app_generator.rb
@@ -143,6 +143,7 @@ def config_when_updating
       @config_target_version = Rails.application.config.loaded_config_version || "5.0"
 
       config
+      configru
 
       unless cookie_serializer_config_exist
         gsub_file "config/initializers/cookies_serializer.rb", /json(?!,)/, "marshal"
diff --git a/railties/lib/rails/generators/rails/app/templates/config.ru.tt b/railties/lib/rails/generators/rails/app/templates/config.ru.tt
index 441e6ff0c3cd5..4a3c09a6889a9 100644
--- a/railties/lib/rails/generators/rails/app/templates/config.ru.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config.ru.tt
@@ -3,3 +3,4 @@
 require_relative "config/environment"
 
 run Rails.application
+Rails.application.load_server
diff --git a/railties/lib/rails/railtie.rb b/railties/lib/rails/railtie.rb
index baf1c1674785f..1e74b22cfb000 100644
--- a/railties/lib/rails/railtie.rb
+++ b/railties/lib/rails/railtie.rb
@@ -108,6 +108,23 @@ module Rails
   # Since filenames on the load path are shared across gems, be sure that files you load
   # through a railtie have unique names.
   #
+  # == Run another program when the Rails server starts
+  #
+  # In development, it's very usual to have to run another process next to the Rails Server. In example
+  # you might want to start the Webpack or React server. Or maybe you need to run your job scheduler process
+  # like Sidekiq. This is usually done by opening a new shell and running the program from here.
+  #
+  # Rails allow you to specify a +server+ block which will get called when a Rails server starts.
+  # This way, your users don't need to remember to have to open a new shell and run another program, making
+  # this less confusing for everyone.
+  # It can be used like this:
+  #
+  # class MyRailtie < Rails::Railtie
+  #   server do
+  #     WebpackServer.start
+  #   end
+  # end
+  #
   # == Application and Engine
   #
   # An engine is nothing more than a railtie with some initializers already set. And since
@@ -152,6 +169,10 @@ def generators(&blk)
         register_block_for(:generators, &blk)
       end
 
+      def server(&blk)
+        register_block_for(:server, &blk)
+      end
+
       def abstract_railtie?
         ABSTRACT_RAILTIES.include?(name)
       end
@@ -246,6 +267,10 @@ def run_tasks_blocks(app) #:nodoc:
         each_registered_block(:rake_tasks) { |block| instance_exec(app, &block) }
       end
 
+      def run_server_blocks(app) #:nodoc:
+        each_registered_block(:server) { |block| block.call(app) }
+      end
+
     private
       # run `&block` in every registered block in `#register_block_for`
       def each_registered_block(type, &block)
diff --git a/railties/test/application/server_test.rb b/railties/test/application/server_test.rb
index 1aa7003906c68..9813cc62c4c75 100644
--- a/railties/test/application/server_test.rb
+++ b/railties/test/application/server_test.rb
@@ -42,6 +42,32 @@ def teardown
       end
     end
 
+    test "run +server+ blocks after the server starts" do
+      skip "PTY unavailable" unless available_pty?
+
+      File.open("#{app_path}/config/boot.rb", "w") do |f|
+        f.puts "ENV['BUNDLE_GEMFILE'] = '#{Bundler.default_gemfile}'"
+        f.puts 'require "bundler/setup"'
+      end
+
+      add_to_config(<<~CODE)
+        server do
+          puts 'Hello world'
+        end
+      CODE
+
+      primary, replica = PTY.open
+      pid = nil
+
+      Bundler.with_original_env do
+        pid = Process.spawn("bin/rails server -b localhost", chdir: app_path, in: replica, out: primary, err: replica)
+        assert_output("Hello world", primary)
+        assert_output("Listening", primary)
+      ensure
+        kill(pid) if pid
+      end
+    end
+
     private
       def kill(pid)
         Process.kill("TERM", pid)
diff --git a/railties/test/railties/railtie_test.rb b/railties/test/railties/railtie_test.rb
index b9725ca0ad79c..845f500ce35cb 100644
--- a/railties/test/railties/railtie_test.rb
+++ b/railties/test/railties/railtie_test.rb
@@ -170,6 +170,22 @@ class MyTie < Rails::Railtie
       assert $ran_block
     end
 
+    test "server block is executed when MyApp.load_server is called" do
+      $ran_block = false
+
+      class MyTie < Rails::Railtie
+        server do
+          $ran_block = true
+        end
+      end
+
+      require "#{app_path}/config/environment"
+
+      assert_not $ran_block
+      Rails.application.load_server
+      assert $ran_block
+    end
+
     test "runner block is executed when MyApp.load_runner is called" do
       $ran_block = false