diff --git a/.eslintrc.js b/.eslintrc.js
new file mode 100644
index 000000000..d0405b751
--- /dev/null
+++ b/.eslintrc.js
@@ -0,0 +1,16 @@
+module.exports = {
+  env: {
+    browser: true,
+    es6: true,
+  },
+  extends: 'eslint:recommended',
+  globals: {
+    Atomics: 'readonly',
+    SharedArrayBuffer: 'readonly',
+  },
+  parserOptions: {
+    ecmaVersion: 2018,
+    sourceType: 'module',
+  },
+  rules: {},
+};
diff --git a/Gemfile b/Gemfile
index be3c31389..4f4ea1e01 100644
--- a/Gemfile
+++ b/Gemfile
@@ -88,7 +88,7 @@ gem "sass-rails", "~> 6.0" # Sass adapter for the Rails asset pipeline
 gem "sidekiq", "~> 6.0.4" # Sidekiq is used to process background jobs with the help of Redis
 gem "sitemap_generator", "~> 6.1" # SitemapGenerator is a framework-agnostic XML Sitemap generator
 gem "slack-notifier", "~> 2.3" # A slim ruby wrapper for posting to slack webhooks
-gem "sprockets", "~> 3.7" # Sprockets is a Rack-based asset packaging system
+gem "sprockets", "~> 4.0" # Sprockets is a Rack-based asset packaging system
 gem "staccato", "~> 0.5" # Ruby Google Analytics Measurement
 gem "storext", "~> 3.1" # Add type-casting and other features on top of ActiveRecord::Store.store_accessor
 gem "stripe", "~> 5.15" # Ruby library for the Stripe API
diff --git a/Gemfile.lock b/Gemfile.lock
index 3eea16106..0b5442ad0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -740,7 +740,7 @@ GEM
     spring (2.1.0)
     spring-commands-rspec (1.0.4)
       spring (>= 0.9.1)
-    sprockets (3.7.2)
+    sprockets (4.0.0)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     sprockets-rails (3.2.1)
@@ -963,7 +963,7 @@ DEPENDENCIES
   slack-notifier (~> 2.3)
   spring (~> 2.1)
   spring-commands-rspec (~> 1.0)
-  sprockets (~> 3.7)
+  sprockets (~> 4.0)
   staccato (~> 0.5)
   stackprof (~> 0.2)
   storext (~> 3.1)
diff --git a/app/assets/config/manifest.js b/app/assets/config/manifest.js
new file mode 100644
index 000000000..5fbbb5019
--- /dev/null
+++ b/app/assets/config/manifest.js
@@ -0,0 +1,6 @@
+// https://github.com/rails/sprockets/blob/master/UPGRADING.md#manifestjs
+//= link_tree ../images
+//= link_directory ../javascripts .js
+//= link_directory ../stylesheets .css
+//= link internal/layout.css
+//= link s3_direct_upload.js
diff --git a/config/initializers/assets.rb b/config/initializers/assets.rb
index 7da6b0738..9c6dcea8e 100644
--- a/config/initializers/assets.rb
+++ b/config/initializers/assets.rb
@@ -10,27 +10,6 @@ Rails.application.config.assets.version = "1.1"
 Rails.application.config.assets.paths << Rails.root.join("node_modules")
 
 # 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 )
-Rails.application.config.assets.precompile += %w[favicon.ico]
-# Add client/assets/ folders to asset pipeline's search path.
-# If you do not want to move existing images and fonts from your Rails app
-# you could also consider creating symlinks there that point to the original
-# rails directories. In that case, you would not add these paths here.
-# Rails.application.config.assets.paths << Rails.root.join("client/assets/stylesheets")
-# Rails.application.config.assets.paths << Rails.root.join("client/assets/images")
-# Rails.application.config.assets.paths << Rails.root.join("client/assets/fonts")
-# Rails.application.config.assets.precompile += %w( generated/server-bundle.js )
-
-Rails.application.config.assets.precompile += %w[minimal.css]
-Rails.application.config.assets.precompile += %w[s3_direct_upload.css]
-Rails.application.config.assets.precompile += %w[base.js]
-Rails.application.config.assets.precompile += %w[hello-dev.js]
-Rails.application.config.assets.precompile += %w[s3_direct_upload.js]
-Rails.application.config.assets.precompile += %w[classified_listings.css]
-Rails.application.config.assets.precompile += %w[lib/xss.js]
-Rails.application.config.assets.precompile += %w[lib/pulltorefresh.js]
-Rails.application.config.assets.precompile += %w[internal.js]
-Rails.application.config.assets.precompile += %w[internal/layout]
-Rails.application.config.assets.precompile << /\.(?:svg|eot|woff|ttf)\z/
-Rails.application.config.assets.precompile += %w[honeybadger-js/dist/honeybadger.js]
+# 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/package.json b/package.json
index 36d93b068..c27556d12 100644
--- a/package.json
+++ b/package.json
@@ -21,6 +21,10 @@
     }
   },
   "lint-staged": {
+    "app/assets/config/manifest.js": [
+      "prettier --write",
+      "eslint --fix -c app/assets/javascripts/.eslintrc.js"
+    ],
     "*.{js,jsx}": [
       "prettier --write",
       "eslint --fix"