diff --git a/Gemfile b/Gemfile
index ed20a87bb..aec824937 100644
--- a/Gemfile
+++ b/Gemfile
@@ -74,7 +74,6 @@ gem 'sib-api-v3-sdk'
 gem 'skylight'
 gem 'smart_listing'
 gem 'spreadsheet_architect'
-gem 'sprockets', '< 4'
 gem 'typhoeus'
 gem 'warden'
 gem 'webpacker'
@@ -112,7 +111,6 @@ group :development do
   gem 'rubocop-rspec-focused', require: false
   gem 'scss_lint', require: false
   gem 'web-console'
-  gem 'xray-rails'
 end
 
 group :development, :test do
diff --git a/Gemfile.lock b/Gemfile.lock
index b559be011..374f79742 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -730,7 +730,7 @@ GEM
     spring (2.1.1)
     spring-commands-rspec (1.0.4)
       spring (>= 0.9.1)
-    sprockets (3.7.2)
+    sprockets (4.0.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     sprockets-rails (3.2.2)
@@ -799,8 +799,6 @@ GEM
     websocket-extensions (0.1.5)
     xpath (3.2.0)
       nokogiri (~> 1.8)
-    xray-rails (0.3.2)
-      rails (>= 3.1.0)
     zeitwerk (2.4.2)
     zip_tricks (5.5.0)
     zipline (1.3.0)
@@ -918,7 +916,6 @@ DEPENDENCIES
   spreadsheet_architect
   spring
   spring-commands-rspec
-  sprockets (< 4)
   timecop
   typhoeus
   vcr
@@ -927,7 +924,6 @@ DEPENDENCIES
   webdrivers (~> 4.0)
   webmock
   webpacker
-  xray-rails
   zipline
   zxcvbn-ruby
 
diff --git a/app/assets/config/manifest.js b/app/assets/config/manifest.js
new file mode 100644
index 000000000..8890f53b3
--- /dev/null
+++ b/app/assets/config/manifest.js
@@ -0,0 +1,5 @@
+//= link application.css
+//= link_tree ../images
+//= link_tree ../fonts
+//= link administrate/application.css
+//= link administrate/application.js
diff --git a/app/assets/stylesheets/application.scss b/app/assets/stylesheets/application.scss
index eaf0c0b98..1fc589860 100644
--- a/app/assets/stylesheets/application.scss
+++ b/app/assets/stylesheets/application.scss
@@ -5,4 +5,3 @@
 // = require ./fonts
 // = require leaflet
 // = require_tree .
-// = stub ./print.scss
diff --git a/app/assets/stylesheets/print.scss b/app/assets/stylesheets/print.scss
index cbb30fc56..4c0e9749c 100644
--- a/app/assets/stylesheets/print.scss
+++ b/app/assets/stylesheets/print.scss
@@ -1,63 +1,65 @@
 @import "colors";
 @import "fonts";
 
-.new-header,
-.sub-header,
-footer {
-  display: none;
-}
-
-.print-header {
-  display: block;
-  margin-top: 30px;
-  font-size: 30px;
-  line-height: 50px;
-  font-weight: bold;
-}
-
-body {
-  font-family: "Muli";
-}
-
-.subtitle {
-  margin-top: -20px;
-  color: $dark-grey;
-}
-
-th,
-td {
-  vertical-align: top;
-}
-
-th {
-  text-align: left;
-
-  &.header-section {
-    padding-top: 1.2em;
-    font-size: 1.2em;
+@media print {
+  .new-header,
+  .sub-header,
+  footer {
+    display: none;
   }
-}
 
-.messagerie {
-  .messages-list {
-    list-style: none;
-    padding-left: 0;
-    max-height: none;
+  .print-header {
+    display: block;
+    margin-top: 30px;
+    font-size: 30px;
+    line-height: 50px;
+    font-weight: bold;
+  }
 
-    h2 {
-      font-size: 110%;
-    }
+  body {
+    font-family: "Muli";
+  }
 
-    .person-icon {
-      display: none;
+  .subtitle {
+    margin-top: -20px;
+    color: $dark-grey;
+  }
+
+  th,
+  td {
+    vertical-align: top;
+  }
+
+  th {
+    text-align: left;
+
+    &.header-section {
+      padding-top: 1.2em;
+      font-size: 1.2em;
     }
   }
-}
 
-.message {
-  margin-bottom: 40px;
-}
+  .messagerie {
+    .messages-list {
+      list-style: none;
+      padding-left: 0;
+      max-height: none;
 
-.updated-at {
-  display: none;
+      h2 {
+        font-size: 110%;
+      }
+
+      .person-icon {
+        display: none;
+      }
+    }
+  }
+
+  .message {
+    margin-bottom: 40px;
+  }
+
+  .updated-at {
+    display: none;
+  }
 }
diff --git a/app/views/layouts/application.html.haml b/app/views/layouts/application.html.haml
index d2ed48a5c..28285f2ea 100644
--- a/app/views/layouts/application.html.haml
+++ b/app/views/layouts/application.html.haml
@@ -20,7 +20,6 @@
     = preload_link_tag(asset_url("Muli-Bold.woff2"))
 
     = stylesheet_link_tag 'application', media: 'all'
-    = stylesheet_link_tag 'print', media: 'print'
 
     = Gon::Base.render_data(camel_case: true, init: true, nonce:  request.content_security_policy_nonce)
 
diff --git a/config/initializers/assets.rb b/config/initializers/assets.rb
index c97536ee3..86d374be3 100644
--- a/config/initializers/assets.rb
+++ b/config/initializers/assets.rb
@@ -10,5 +10,6 @@ Rails.application.config.assets.paths << Rails.root.join('node_modules', '@reach
 Rails.application.config.assets.paths << Rails.root.join('node_modules', '@mapbox', 'mapbox-gl-draw', 'dist')
 
 # Precompile additional assets.
-# application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
-Rails.application.config.assets.precompile += ['print.css']
+# application.js, application.css, and all non-JS/CSS in the app/assets
+# folder are already added.
+# Rails.application.config.assets.precompile += %w( admin.js admin.css )
diff --git a/config/initializers/sentry.rb b/config/initializers/sentry.rb
index a65106b50..2d4008a4f 100644
--- a/config/initializers/sentry.rb
+++ b/config/initializers/sentry.rb
@@ -3,5 +3,5 @@ Sentry.init do |config|
   config.send_default_pii = false
   config.enabled_environments = ['production']
   config.breadcrumbs_logger = [:active_support_logger]
-  config.traces_sample_rate = 0.001
+  config.traces_sample_rate = ENV['SENTRY_ENABLED'] == 'enabled' ? 0.001 : nil
 end