diff --git a/lib/dry/rails.rb b/lib/dry/rails.rb
index c7551e0..6830b09 100644
--- a/lib/dry/rails.rb
+++ b/lib/dry/rails.rb
@@ -1,8 +1,7 @@
 # frozen_string_literal: true
 
 require "dry/rails/railtie"
-require "dry/rails/container"
-require "dry/rails/components"
+require "dry/rails/engine"
 
 module Dry
   # Initializer interface
@@ -18,14 +17,17 @@ module Dry
   #
   # @api public
   module Rails
+    extend Dry::Configurable
+    setting :main_app_name
+    setting :main_app_enabled, default: true
+
     # Set container block that will be evaluated in the context of the container
     #
     # @return [self]
     #
     # @api public
     def self.container(&block)
-      _container_blocks << block
-      self
+      Engine.container(config.main_app_name, &block)
     end
 
     # Create a new container class
@@ -38,19 +40,12 @@ def self.container(&block)
     #
     # @api private
     def self.create_container(options = {})
-      Class.new(Container) { config.update(options) }
+      Engine.create_container(options)
     end
 
     # @api private
     def self.evaluate_initializer(container)
-      _container_blocks.each do |block|
-        container.class_eval(&block)
-      end
-    end
-
-    # @api private
-    def self._container_blocks
-      @_container_blocks ||= []
+      Engine.evaluate_initializer(config.main_app_name, container)
     end
   end
 end
diff --git a/lib/dry/rails/boot/safe_params.rb b/lib/dry/rails/boot/safe_params.rb
index f0c014d..4fd21c2 100644
--- a/lib/dry/rails/boot/safe_params.rb
+++ b/lib/dry/rails/boot/safe_params.rb
@@ -6,7 +6,7 @@
   end
 
   start do
-    ApplicationController.include(Dry::Rails::Features::SafeParams)
+    ActionController::Base.include(Dry::Rails::Features::SafeParams)
 
     if defined?(ActionController::API)
       ActionController::API.include(Dry::Rails::Features::SafeParams)
diff --git a/lib/dry/rails/container.rb b/lib/dry/rails/container.rb
index ae4b6be..982c7d1 100644
--- a/lib/dry/rails/container.rb
+++ b/lib/dry/rails/container.rb
@@ -27,7 +27,7 @@ class Container < System::Container
       #
       #   @api public
       # @!scope class
-      setting :features, %i[application_contract safe_params controller_helpers], reader: true
+      setting :features, default: %i[application_contract safe_params controller_helpers], reader: true
 
       # @overload config.auto_register_paths=(paths)
       #   Set an array of path/block pairs for auto-registration
@@ -39,7 +39,7 @@ class Container < System::Container
       #
       #   @api public
       # @!scope class
-      setting :auto_register_paths, [].freeze, reader: true
+      setting :auto_register_paths, default: [].freeze, reader: true
 
       # @overload config.auto_inject_constant=(auto_inject_constant)
       #   Set a custom import constant name
@@ -48,7 +48,7 @@ class Container < System::Container
       #
       #   @api public
       # @!scope class
-      setting :auto_inject_constant, "Deps", reader: true
+      setting :auto_inject_constant, default: "Deps", reader: true
 
       # @overload config.container_constant=(container_constant)
       #   Set a custom container constant
@@ -57,7 +57,7 @@ class Container < System::Container
       #
       #   @api public
       # @!scope class
-      setting :container_constant, "Container", reader: true
+      setting :container_constant, default: "Container", reader: true
 
       # @!endgroup
 
diff --git a/lib/dry/rails/engine.rb b/lib/dry/rails/engine.rb
new file mode 100644
index 0000000..d12eb78
--- /dev/null
+++ b/lib/dry/rails/engine.rb
@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require "dry/rails/container"
+require "dry/rails/components"
+
+module Dry
+  module Rails
+    module Engine
+      # Set container block that will be evaluated in the context of the container
+      #
+      # @param name [Symbol]
+      # @return [self]
+      #
+      # @api public
+      def self.container(name, &block)
+        _container_blocks[name] << block
+        self
+      end
+
+      # Create a new container class
+      #
+      # This is used during booting and reloading
+      #
+      # @param name [Symbol]
+      # @param options [Hash] Container configuration settings
+      #
+      # @return [Class]
+      #
+      # @api private
+      def self.create_container(options = {})
+        Class.new(Container) { config.update(options) }
+      end
+
+      # @api private
+      def self.evaluate_initializer(name, container)
+        _container_blocks[name].each do |block|
+          container.class_eval(&block)
+        end
+      end
+
+      # @api private
+      def self._container_blocks
+        @_container_blocks ||= Hash.new { |h, k| h[k] = [] }
+      end
+    end
+  end
+end
diff --git a/lib/dry/rails/finalizer.rb b/lib/dry/rails/finalizer.rb
new file mode 100644
index 0000000..0d91311
--- /dev/null
+++ b/lib/dry/rails/finalizer.rb
@@ -0,0 +1,170 @@
+# frozen_string_literal: true
+
+module Dry
+  module Rails
+    class Finalizer
+      def self.app_namespace_to_name(app_namespace)
+        app_namespace.name.underscore.to_sym
+      end
+
+      def initialize(
+        railtie:,
+        app_namespace:,
+        root_path:,
+        name: Dry::Rails.config.main_app_name,
+        container_const_name: Dry::Rails::Container.container_constant,
+        default_inflector: ActiveSupport::Inflector
+      )
+        @railtie = railtie
+        @app_namespace = app_namespace
+        @root_path = root_path
+        @name = name
+        @container_const_name = container_const_name
+        @default_inflector = default_inflector
+      end
+
+      attr_reader :railtie,
+                  :root_path,
+                  :container_const_name
+
+      # Infer the default application namespace
+      #
+      # TODO: we had to rename namespace=>app_namespace because
+      #       Rake::DSL's Kernel#namespace *sometimes* breaks things.
+      #       Currently we are missing specs verifying that rake tasks work
+      #       correctly and those must be added!
+      #
+      # @return [Module]
+      #
+      # @api public
+      attr_reader :app_namespace
+
+      # Code-reloading-aware finalization process
+      #
+      # This sets up `Container` and `Deps` constants, reloads them if this is in reloading mode,
+      # and registers default components like the railtie itself or the inflector
+      #
+      # @api public
+      #
+      # rubocop:disable Metrics/AbcSize
+      def finalize!
+        stop_features if reloading?
+
+        container = Dry::Rails::Engine.create_container(
+          root: root_path,
+          name: name,
+          default_namespace: name.to_s,
+          inflector: default_inflector,
+          system_dir: root_path.join("config/system"),
+          bootable_dirs: [root_path.join("config/system/boot")]
+        )
+
+        # Enable :env plugin by default because it is a very common requirement
+        container.use :env, inferrer: -> { ::Rails.env }
+
+        container.register(:railtie, railtie)
+        container.register(:inflector, default_inflector)
+
+        # Remove previously defined constants, if any, so we don't end up with
+        # unsused constants in app's namespace when a name change happens.
+        remove_constant(container.auto_inject_constant)
+        remove_constant(container.container_constant)
+
+        Dry::Rails::Engine.evaluate_initializer(name, container)
+
+        @container_const_name = container.container_constant
+
+        set_or_reload(container.container_constant, container)
+        set_or_reload(container.auto_inject_constant, container.injector)
+
+        container.features.each do |feature|
+          container.boot(feature, from: :rails)
+        end
+
+        container.refresh_boot_files if reloading?
+
+        container.finalize!(freeze: !::Rails.env.test?)
+      end
+      # rubocop:enable Metrics/AbcSize
+
+      # Stops all configured features (bootable components)
+      #
+      # This is *crucial* when reloading code in development mode. Every bootable component
+      # should be able to clear the runtime from any constants that it created in its `stop`
+      # lifecycle step
+      #
+      # @api public
+      def stop_features
+        container.features.each do |feature|
+          container.stop(feature) if container.booted?(feature)
+        end
+      end
+
+      # Exposes the container constant
+      #
+      # @return [Dry::Rails::Container]
+      #
+      # @api public
+      def container
+        app_namespace.const_get(container_const_name, false)
+      end
+
+      # Return true if we're in code-reloading mode
+      #
+      # @api private
+      def reloading?
+        app_namespace.const_defined?(container_const_name, false)
+      end
+
+      # Return the default system name
+      #
+      # In the dry-system world containers are explicitly named using symbols, so that you can
+      # refer to them easily when ie importing one container into another
+      #
+      # @return [Symbol]
+      #
+      # @api private
+      attr_reader :name
+
+      # Sets or reloads a constant within the application namespace
+      #
+      # @api private
+      attr_reader :default_inflector
+
+      # @api private
+      def set_or_reload(const_name, const)
+        remove_constant(const_name)
+        app_namespace.const_set(const_name, const)
+      end
+
+      # @api private
+      def remove_constant(const_name)
+        if app_namespace.const_defined?(const_name, false)
+          app_namespace.__send__(:remove_const, const_name)
+        end
+      end
+    end
+
+    module Engine
+      class Finalizer
+        def self.new(
+          railtie:,
+          app_namespace:,
+          root_path:,
+          name: nil,
+          container_const_name: Dry::Rails::Container.container_constant,
+          default_inflector: ActiveSupport::Inflector
+        )
+          Dry::Rails::Finalizer.new(
+            railtie: railtie,
+            app_namespace: app_namespace,
+            root_path: root_path,
+            name: name || ::Dry::Rails::Finalizer.app_namespace_to_name(app_namespace),
+            container_const_name: container_const_name,
+            default_inflector: default_inflector
+          )
+        end
+      end
+    end
+  end
+end
diff --git a/lib/dry/rails/railtie.rb b/lib/dry/rails/railtie.rb
index 10a2a14..37f5d2b 100644
--- a/lib/dry/rails/railtie.rb
+++ b/lib/dry/rails/railtie.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "rails/railtie"
+require "dry/rails/finalizer"
 
 module Dry
   module Rails
@@ -8,12 +9,31 @@ module Rails
     #
     # @api public
     class Railtie < ::Rails::Railtie
-      attr_reader :container_const_name
-
       # This is needed because `finalize!` can reload code and this hook is called every-time
       # in development env upon a request (in production it's called just once during booting)
       config.to_prepare do
-        Railtie.finalize!
+        Railtie.finalize! if Dry::Rails.config.main_app_enabled
+      end
+
+      initializer "dry-rails.main-app-container" do
+        Dry::Rails.config.main_app_name = Dry::Rails::Finalizer.app_namespace_to_name(app_namespace)
+      end
+
+      # Infer the default application namespace
+      #
+      # TODO: we had to rename namespace=>app_namespace because
+      #       Rake::DSL's Kernel#namespace *sometimes* breaks things.
+      #       Currently we are missing specs verifying that rake tasks work
+      #       correctly and those must be added!
+      #
+      # @return [Module]
+      #
+      # @api public
+      def app_namespace
+        @app_namespace ||= begin
+          top_level_namespace = ::Rails.application.class.to_s.split("::").first
+          Object.const_get(top_level_namespace)
+        end
       end
 
       # Code-reloading-aware finalization process
@@ -22,51 +42,7 @@ class Railtie < ::Rails::Railtie
       # and registers default components like the railtie itself or the inflector
       #
       # @api public
-      #
-      # rubocop:disable Metrics/AbcSize
-      def finalize!
-        @container_const_name ||= Dry::Rails::Container.container_constant
-
-        stop_features if reloading?
-
-        root_path = ::Rails.root
-
-        container = Dry::Rails.create_container(
-          root: root_path,
-          name: name,
-          default_namespace: name.to_s,
-          inflector: default_inflector,
-          system_dir: root_path.join("config/system"),
-          bootable_dirs: [root_path.join("config/system/boot")]
-        )
-
-        # Enable :env plugin by default because it is a very common requirement
-        container.use :env, inferrer: -> { ::Rails.env }
-
-        container.register(:railtie, self)
-        container.register(:inflector, default_inflector)
-
-        # Remove previously defined constants, if any, so we don't end up with
-        # unsused constants in app's namespace when a name change happens.
-        remove_constant(container.auto_inject_constant)
-        remove_constant(container.container_constant)
-
-        Dry::Rails.evaluate_initializer(container)
-
-        @container_const_name = container.container_constant
-
-        set_or_reload(container.container_constant, container)
-        set_or_reload(container.auto_inject_constant, container.injector)
-
-        container.features.each do |feature|
-          container.boot(feature, from: :rails)
-        end
-
-        container.refresh_boot_files if reloading?
-
-        container.finalize!(freeze: !::Rails.env.test?)
-      end
-      # rubocop:enable Metrics/AbcSize
+      delegate :finalize!, to: :finalizer
       alias_method :reload, :finalize!
 
       # Stops all configured features (bootable components)
@@ -76,75 +52,29 @@ def finalize!
       # lifecycle step
       #
       # @api public
-      def stop_features
-        container.features.each do |feature|
-          container.stop(feature) if container.booted?(feature)
-        end
-      end
+      delegate :stop_features, to: :finalizer
 
       # Exposes the container constant
       #
       # @return [Dry::Rails::Container]
       #
       # @api public
-      def container
-        app_namespace.const_get(container_const_name, false)
-      end
+      delegate :container, to: :finalizer
 
-      # Return true if we're in code-reloading mode
-      #
       # @api private
-      def reloading?
-        app_namespace.const_defined?(container_const_name, false)
-      end
+      delegate :set_or_reload, to: :finalizer
 
-      # Return the default system name
-      #
-      # In the dry-system world containers are explicitly named using symbols, so that you can
-      # refer to them easily when ie importing one container into another
-      #
-      # @return [Symbol]
-      #
       # @api private
-      def name
-        app_namespace.name.underscore.to_sym
-      end
+      delegate :remove_constant, to: :finalizer
 
-      # Infer the default application namespace
-      #
-      # TODO: we had to rename namespace=>app_namespace because
-      #       Rake::DSL's Kernel#namespace *sometimes* breaks things.
-      #       Currently we are missing specs verifying that rake tasks work
-      #       correctly and those must be added!
-      #
-      # @return [Module]
-      #
-      # @api public
-      def app_namespace
-        @app_namespace ||= begin
-          top_level_namespace = ::Rails.application.class.to_s.split("::").first
-          Object.const_get(top_level_namespace)
-        end
-      end
+      private
 
-      # Sets or reloads a constant within the application namespace
-      #
-      # @api private
-      def default_inflector
-        ActiveSupport::Inflector
-      end
-
-      # @api private
-      def set_or_reload(const_name, const)
-        remove_constant(const_name)
-        app_namespace.const_set(const_name, const)
-      end
-
-      # @api private
-      def remove_constant(const_name)
-        if app_namespace.const_defined?(const_name, false)
-          app_namespace.__send__(:remove_const, const_name)
-        end
+      def finalizer
+        @finalizer ||= Finalizer.new(
+          railtie: self,
+          app_namespace: app_namespace,
+          root_path: ::Rails.root
+        )
       end
     end
   end
diff --git a/spec/dummy-6.x/dummy/config/environments/test.rb b/spec/dummy-6.x/dummy/config/environments/test.rb
index bae3b39..c045a26 100644
--- a/spec/dummy-6.x/dummy/config/environments/test.rb
+++ b/spec/dummy-6.x/dummy/config/environments/test.rb
@@ -18,7 +18,7 @@
   # Configure public file server for tests with Cache-Control for performance.
   config.public_file_server.enabled = true
   config.public_file_server.headers = {
-    "Cache-Control" => "public, max-age=#{1.hour.to_i}"
+    "Cache-Control" => "public, max-age=3600"
   }
 
   # Show full error reports and disable caching.