diff --git a/CHANGELOG.md b/CHANGELOG.md
index bd40b67f2..8ec701a71 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+04.06.2020
+* Moved dev config to sample file [#1599](https://github.com/internetee/registry/pull/1599)
+
+03.06.2020
+* Upgraded Rails to 6.0.3 [#1593](https://github.com/internetee/registry/pull/1593)
+
 02.06.2020
 * Fixed registration deadline format for whois/restwhois [#1595](https://github.com/internetee/registry/pull/1595)
 
diff --git a/config/environments/development.rb.sample b/config/environments/development.rb.sample
index d052f69c0..377f2cbbd 100644
--- a/config/environments/development.rb.sample
+++ b/config/environments/development.rb.sample
@@ -9,32 +9,59 @@ Rails.application.configure do
   # Do not eager load code on boot.
   config.eager_load = false
 
-  # Show full error reports and disable caching.
+  # Show full error reports.
   config.consider_all_requests_local = true
-  config.action_controller.perform_caching = false
+
+  # Enable/disable caching. By default caching is disabled.
+  # Run rails dev:cache to toggle caching.
+  if Rails.root.join('tmp', 'caching-dev.txt').exist?
+    config.action_controller.perform_caching = true
+    config.action_controller.enable_fragment_cache_logging = true
+
+    config.cache_store = :memory_store
+    config.public_file_server.headers = {
+      'Cache-Control' => "public, max-age=#{2.days.to_i}"
+    }
+  else
+    config.action_controller.perform_caching = false
+
+    config.cache_store = :null_store
+  end
+
+  # Store uploaded files on the local file system (see config/storage.yml for options).
+  config.active_storage.service = :local
+
+  # Don't care if the mailer can't send.
+  config.action_mailer.raise_delivery_errors = false
+
+  config.action_mailer.perform_caching = false
 
   # Print deprecation notices to the Rails logger.
   config.active_support.deprecation = :log
 
-  config.logger = ActiveSupport::Logger.new(nil)
-
   # Raise an error on page load if there are pending migrations.
   config.active_record.migration_error = :page_load
 
+  # Highlight code that triggered database queries in logs.
+  config.active_record.verbose_query_logs = true
+
   # 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 = false
+  config.assets.debug = 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
-
-  config.action_view.raise_on_missing_translations = true
+  # Suppress logger output for asset requests.
+  config.assets.quiet = true
 
   # Allow any host to access development
   config.hosts.clear
+
+  # Raises error for missing translations.
+  # config.action_view.raise_on_missing_translations = true
+
+  # Use an evented file watcher to asynchronously detect changes in source code,
+  # routes, locales, etc. This feature depends on the listen gem.
+  config.file_watcher = ActiveSupport::EventedFileUpdateChecker
 end
 
 # In this mode, any jobs you queue will be run in the same thread, synchronously
diff --git a/config/initializers/assets.rb b/config/initializers/assets.rb
index 0794e55a4..d5a05217a 100644
--- a/config/initializers/assets.rb
+++ b/config/initializers/assets.rb
@@ -6,4 +6,7 @@ Rails.application.configure do
 
   # Add additional assets to the asset load path
   config.assets.paths << Rails.root.join('vendor', 'assets', 'fonts', 'node_modules')
+
+  # Precompile additional assets.
+  # application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
 end