diff --git a/.gitignore b/.gitignore
index 75308ca..ab6086b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,7 @@
 /Gemfile-custom.rb
 /Gemfile.lock
 /config/database.yml
+/config/secrets.yml
 /data/
 /log/*.log
 /tmp/
diff --git a/Gemfile b/Gemfile
index d0618fd..0640c05 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-gem 'rails',  '~> 4.0'
+gem 'rails',  '~> 4.2.1'
 gem 'pg',     '~> 0.17'
 gem 'haml',   '~> 4.0'
 gem 'bcrypt', '~> 3.0'
diff --git a/bin/rails b/bin/rails
index 71755b8..fad8d8b 100755
--- a/bin/rails
+++ b/bin/rails
@@ -1,5 +1,5 @@
 #!/usr/bin/env ruby
 
-APP_PATH = File.expand_path('../../config/application',  __FILE__)
+APP_PATH = File.expand_path('../../config/application', __FILE__)
 require_relative '../config/boot'
 require 'rails/commands'
diff --git a/config/application.rb b/config/application.rb
index d6d9e6d..55cb828 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -19,5 +19,8 @@ module Scube
     # The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
     # config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
     # config.i18n.default_locale = :de
+
+    # Do not swallow errors in after_commit/after_rollback callbacks.
+    config.active_record.raise_in_transactional_callbacks = true
   end
 end
diff --git a/config/boot.rb b/config/boot.rb
index 5e5f0c1..6b750f0 100644
--- a/config/boot.rb
+++ b/config/boot.rb
@@ -1,4 +1,3 @@
-# Set up gems listed in the Gemfile.
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
 
-require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
+require 'bundler/setup' # Set up gems listed in the Gemfile.
diff --git a/config/environment.rb b/config/environment.rb
index 5eb742d..ee8d90d 100644
--- a/config/environment.rb
+++ b/config/environment.rb
@@ -2,4 +2,4 @@
 require File.expand_path('../application', __FILE__)
 
 # Initialize the Rails application.
-Scube::Application.initialize!
+Rails.application.initialize!
diff --git a/config/environments/development.rb b/config/environments/development.rb
index 45657fe..b55e214 100644
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -1,4 +1,4 @@
-Scube::Application.configure do
+Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
   # In the development environment your application's code is reloaded on
@@ -19,11 +19,23 @@ Scube::Application.configure do
   # Print deprecation notices to the Rails logger.
   config.active_support.deprecation = :log
 
-  # Raise an error on page load if there are pending migrations
+  # Raise an error on page load if there are pending migrations.
   config.active_record.migration_error = :page_load
 
   # Debug mode disables concatenation and preprocessing of assets.
   # This option may cause significant delays in view rendering with a large
   # number of complex assets.
   config.assets.debug = true
+
+  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
+  # yet still be able to expire them through the digest params.
+  config.assets.digest = true
+
+  # Adds additional error checking when serving assets at runtime.
+  # Checks for improperly declared sprockets dependencies.
+  # Raises helpful error messages.
+  config.assets.raise_runtime_errors = true
+
+  # Raises error for missing translations
+  # config.action_view.raise_on_missing_translations = true
 end
diff --git a/config/environments/production.rb b/config/environments/production.rb
index ea700d0..2aa88a8 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -1,11 +1,11 @@
-Scube::Application.configure do
+Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
   # Code is not reloaded between requests.
   config.cache_classes = true
 
   # Eager load code on boot. This eager loads most of Rails and
-  # your application in memory, allowing both thread web servers
+  # your application in memory, allowing both threaded web servers
   # and those relying on copy on write to perform better.
   # Rake tasks automatically ignore this option for performance.
   config.eager_load = true
@@ -16,11 +16,13 @@ Scube::Application.configure do
 
   # Enable Rack::Cache to put a simple HTTP cache in front of your application
   # Add `rack-cache` to your Gemfile before enabling this.
-  # For large-scale production use, consider using a caching reverse proxy like nginx, varnish or squid.
+  # For large-scale production use, consider using a caching reverse proxy like
+  # NGINX, varnish or squid.
   # config.action_dispatch.rack_cache = true
 
-  # Disable Rails's static asset server (Apache or nginx will already do this).
-  config.serve_static_assets = false
+  # Disable serving static files from the `/public` folder by default since
+  # Apache or NGINX already handles this.
+  config.serve_static_files = ENV['RAILS_SERVE_STATIC_FILES'].present?
 
   # Compress JavaScripts and CSS.
   config.assets.js_compressor = :uglifier
@@ -29,20 +31,21 @@ Scube::Application.configure do
   # Do not fallback to assets pipeline if a precompiled asset is missed.
   config.assets.compile = false
 
-  # Generate digests for assets URLs.
+  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
+  # yet still be able to expire them through the digest params.
   config.assets.digest = true
 
-  # Version of your assets, change this if you want to expire all your assets.
-  config.assets.version = '1.0'
+  # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb
 
   # Specifies the header that your server uses for sending files.
-  # config.action_dispatch.x_sendfile_header = "X-Sendfile" # for apache
-  # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for nginx
+  # config.action_dispatch.x_sendfile_header = 'X-Sendfile' # for Apache
+  # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX
 
   # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
   # config.force_ssl = true
 
-  # Set to :debug to see everything in the log.
+  # Use the lowest log level to ensure availability of diagnostic information
+  # when problems arise.
   config.log_level = :info
 
   # Prepend all log lines with the following tags.
@@ -55,26 +58,22 @@ Scube::Application.configure do
   # config.cache_store = :mem_cache_store
 
   # Enable serving of images, stylesheets, and JavaScripts from an asset server.
-  # config.action_controller.asset_host = "http://assets.example.com"
-
-  # Precompile additional assets.
-  # application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
-  # config.assets.precompile += %w( search.js )
+  # config.action_controller.asset_host = 'http://assets.example.com'
 
   # Ignore bad email addresses and do not raise email delivery errors.
   # Set this to true and configure the email server for immediate delivery to raise delivery errors.
   # config.action_mailer.raise_delivery_errors = false
 
   # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
-  # the I18n.default_locale when a translation can not be found).
+  # the I18n.default_locale when a translation cannot be found).
   config.i18n.fallbacks = true
 
   # Send deprecation notices to registered listeners.
   config.active_support.deprecation = :notify
 
-  # Disable automatic flushing of the log to improve performance.
-  # config.autoflush_log = false
-
   # Use default logging formatter so that PID and timestamp are not suppressed.
   config.log_formatter = ::Logger::Formatter.new
+
+  # Do not dump schema after migrations.
+  config.active_record.dump_schema_after_migration = false
 end
diff --git a/config/environments/test.rb b/config/environments/test.rb
index 70c5a9e..1c19f08 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -1,4 +1,4 @@
-Scube::Application.configure do
+Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
   # The test environment is used exclusively to run your application's
@@ -12,9 +12,9 @@ Scube::Application.configure do
   # preloads Rails for running tests, you may have to set it to true.
   config.eager_load = false
 
-  # Configure static asset server for tests with Cache-Control for performance.
-  config.serve_static_assets  = true
-  config.static_cache_control = "public, max-age=3600"
+  # Configure static file server for tests with Cache-Control for performance.
+  config.serve_static_files   = true
+  config.static_cache_control = 'public, max-age=3600'
 
   # Show full error reports and disable caching.
   config.consider_all_requests_local       = true
@@ -31,6 +31,12 @@ Scube::Application.configure do
   # ActionMailer::Base.deliveries array.
   config.action_mailer.delivery_method = :test
 
+  # Randomize the order test cases are executed.
+  config.active_support.test_order = :random
+
   # Print deprecation notices to the stderr.
   config.active_support.deprecation = :stderr
+
+  # Raises error for missing translations
+  # config.action_view.raise_on_missing_translations = true
 end
diff --git a/config/initializers/assets.rb b/config/initializers/assets.rb
new file mode 100644
index 0000000..01ef3e6
--- /dev/null
+++ b/config/initializers/assets.rb
@@ -0,0 +1,11 @@
+# Be sure to restart your server when you modify this file.
+
+# Version of your assets, change this if you want to expire all your assets.
+Rails.application.config.assets.version = '1.0'
+
+# Add additional assets to the asset load path
+# Rails.application.config.assets.paths << Emoji.images_path
+
+# Precompile additional assets.
+# application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
+# Rails.application.config.assets.precompile += %w( search.js )
diff --git a/config/initializers/cookies_serializer.rb b/config/initializers/cookies_serializer.rb
new file mode 100644
index 0000000..7f70458
--- /dev/null
+++ b/config/initializers/cookies_serializer.rb
@@ -0,0 +1,3 @@
+# Be sure to restart your server when you modify this file.
+
+Rails.application.config.action_dispatch.cookies_serializer = :json
diff --git a/config/initializers/mime_types.rb b/config/initializers/mime_types.rb
index 72aca7e..dc18996 100644
--- a/config/initializers/mime_types.rb
+++ b/config/initializers/mime_types.rb
@@ -2,4 +2,3 @@
 
 # Add new mime types for use in respond_to blocks:
 # Mime::Type.register "text/richtext", :rtf
-# Mime::Type.register_alias "text/html", :iphone
diff --git a/config/initializers/session_store.rb b/config/initializers/session_store.rb
index bc77e55..449749e 100644
--- a/config/initializers/session_store.rb
+++ b/config/initializers/session_store.rb
@@ -1,3 +1,3 @@
 # Be sure to restart your server when you modify this file.
 
-Scube::Application.config.session_store :cookie_store, key: '_scube_session'
+Rails.application.config.session_store :cookie_store, key: '_scube_session'
diff --git a/config/routes.rb b/config/routes.rb
index d253a8f..19e7381 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -1,4 +1,4 @@
-Scube::Application.routes.draw do
+Rails.application.routes.draw do
   namespace :api do
     resources :sounds, only: [:show]
     resources :tracks, only: [:index]