diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 1614cb4d03a..30b5d4fbcde 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -278,7 +278,7 @@ jobs:
 
       - name: Asset Processor Tests
         if: matrix.build_type == 'frontend' && matrix.target == 'core'
-        working-directory: app/assets/javascripts/asset-processor
+        working-directory: frontend/asset-processor
         run: pnpm test
 
       - name: Plugin QUnit
@@ -292,8 +292,8 @@ jobs:
       - uses: actions/upload-artifact@v4
         if: always() && matrix.build_type == 'frontend'
         with:
-          name: ember-exam-execution-${{ matrix.target }}-${{ matrix.browser }}-frontend-${{ hashFiles('./app/assets/javascripts/discourse/test-execution-*.json') }}
-          path: ./app/assets/javascripts/discourse/test-execution-*.json
+          name: ember-exam-execution-${{ matrix.target }}-${{ matrix.browser }}-frontend-${{ hashFiles('./frontend/discourse/test-execution-*.json') }}
+          path: ./frontend/discourse/test-execution-*.json
 
       - name: Ember Build for System Tests
         if: matrix.build_type == 'system'
diff --git a/.pnpmfile.cjs b/.pnpmfile.cjs
index 4c2d77a81a3..f73af57e741 100644
--- a/.pnpmfile.cjs
+++ b/.pnpmfile.cjs
@@ -19,28 +19,23 @@ if (fs.existsSync(`${discourseRoot}/node_modules/.yarn-integrity`)) {
   console.log("cleanup done");
 }
 
-const oldAdminPath = `${discourseRoot}/app/assets/javascripts/admin`;
-if (fs.existsSync(`${oldAdminPath}/node_modules`)) {
+const oldFrontendPath = `app/assets/javascripts`;
+if (fs.existsSync(`${discourseRoot}/${oldFrontendPath}`)) {
   console.log(
-    "Detected old admin node_modules. Performing one-time cleanup..."
+    `[.pnpmfile.cjs] Detected old ${oldFrontendPath} directory. Cleaning up gitignored files...`
   );
-
-  fs.rmSync(`${oldAdminPath}/node_modules`, {
-    recursive: true,
-  });
+  execSync(`git clean -f -X ${oldFrontendPath}`, { cwd: discourseRoot });
 
   const anyFiles = !!execSync(
-    `find "${oldAdminPath}" -mindepth 1 -type f -print -quit`,
-    { encoding: "utf8" }
+    `find "${oldFrontendPath}" -mindepth 1 -type f -print -quit`,
+    { encoding: "utf8", cwd: discourseRoot }
   ).trim();
 
   if (!anyFiles) {
-    fs.rmSync(oldAdminPath, {
+    fs.rmSync(oldFrontendPath, {
       recursive: true,
     });
   }
-
-  console.log("admin cleanup done");
 }
 
 const pluginBase = `${discourseRoot}/plugins/`;
diff --git a/.prettierignore b/.prettierignore
index 0663ab5c013..fe06c902eb7 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -1,5 +1,4 @@
 app/assets/stylesheets/vendor/
-app/assets/javascripts/plugins/
 plugins/**/assets/stylesheets/vendor/
 plugins/**/assets/javascripts/vendor/
 plugins/**/config/locales/**/*.yml
@@ -10,18 +9,12 @@ config/locales/**/*.yml
 !config/locales/**/*.en*.yml
 script/import_scripts/**/*.yml
 
-app/assets/javascripts/browser-update.js
-app/assets/javascripts/ember-addons/
-app/assets/javascripts/discourse/lib/autosize.js
-lib/javascripts/locale/
-lib/javascripts/messageformat.js
-lib/highlight_js/
 plugins/**/lib/javascripts/locale
 public/
-!/app/assets/javascripts/discourse/public
+!/frontend/discourse/public
 vendor/
-app/assets/javascripts/discourse/tests/unit/utils/decorators-test.js
-app/assets/javascripts/discourse/tests/fixtures
+frontend/discourse/tests/unit/utils/decorators-test.js
+frontend/discourse/tests/fixtures
 spec/
 node_modules/
 dist/
diff --git a/app/assets/javascripts/discourse-plugins/index.js b/app/assets/javascripts/discourse-plugins/index.js
index 7f9cc521dcc..aec0e3dc514 100644
--- a/app/assets/javascripts/discourse-plugins/index.js
+++ b/app/assets/javascripts/discourse-plugins/index.js
@@ -127,7 +127,7 @@ module.exports = {
   },
 
   pluginInfos() {
-    const root = path.resolve("../../../../plugins");
+    const root = path.resolve("../../plugins");
     const pluginDirectories = fs
       .readdirSync(root, { withFileTypes: true })
       .filter(
diff --git a/app/assets/javascripts/discourse/app/lib/keyboard-shortcuts.js b/app/assets/javascripts/discourse/app/lib/keyboard-shortcuts.js
index db4c4a108c0..d273ea622f4 100644
--- a/app/assets/javascripts/discourse/app/lib/keyboard-shortcuts.js
+++ b/app/assets/javascripts/discourse/app/lib/keyboard-shortcuts.js
@@ -263,7 +263,7 @@ export default {
    *                  category: String,
    *                  name: String,
    *                  definition: (See function `buildShortcut` in
-   *                    app/assets/javascripts/discourse/app/controllers/keyboard-shortcuts-help.js
+   *                    frontend/discourse/app/controllers/keyboard-shortcuts-help.js
    *                    for definition structure)
    *                }
    *
diff --git a/app/assets/javascripts/discourse/ember-cli-build.js b/app/assets/javascripts/discourse/ember-cli-build.js
index 19eecc2ca49..7cde0c9cd46 100644
--- a/app/assets/javascripts/discourse/ember-cli-build.js
+++ b/app/assets/javascripts/discourse/ember-cli-build.js
@@ -23,7 +23,7 @@ const { BroccoliMergeFiles } = require("broccoli-merge-files");
 process.env.BROCCOLI_ENABLED_MEMOIZE = true;
 
 module.exports = function (defaults) {
-  const discourseRoot = path.resolve("../../../..");
+  const discourseRoot = path.resolve("../..");
   const vendorJs = discourseRoot + "/vendor/assets/javascripts/";
 
   // Silence deprecations which we are aware of - see `lib/deprecation-silencer.js`
@@ -103,11 +103,10 @@ module.exports = function (defaults) {
   });
 
   // WARNING: We should only import scripts here if they are not in NPM.
-  app.import(discourseRoot + "/app/assets/javascripts/polyfills.js");
+  app.import(discourseRoot + "/frontend/polyfills.js");
 
   app.import(
-    discourseRoot +
-      "/app/assets/javascripts/discourse/public/assets/scripts/module-shims.js"
+    discourseRoot + "/frontend/discourse/public/assets/scripts/module-shims.js"
   );
 
   const discoursePluginsTree = app.project
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 5b43bc5038e..a3dd050c1db 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -734,7 +734,7 @@ class ApplicationController < ActionController::Base
     raise Discourse::InvalidAccess.new unless SiteSetting.wizard_enabled?
   end
 
-  # Keep in sync with `NO_DESTINATION_COOKIE` in `app/assets/javascripts/discourse/app/lib/utilities.js`
+  # Keep in sync with `NO_DESTINATION_COOKIE` in `frontend/discourse/app/lib/utilities.js`
   NO_DESTINATION_COOKIE = %w[/login /signup /session/ /auth/ /uploads/].freeze
 
   def is_valid_destination_url?(url)
diff --git a/app/services/theme_settings_migrations_runner.rb b/app/services/theme_settings_migrations_runner.rb
index c7d1fe85711..6b5fb455f50 100644
--- a/app/services/theme_settings_migrations_runner.rb
+++ b/app/services/theme_settings_migrations_runner.rb
@@ -58,10 +58,7 @@ class ThemeSettingsMigrationsRunner
   def self.loader_js_lib_content
     @loader_js_lib_content ||=
       File.read(
-        File.join(
-          Rails.root,
-          "app/assets/javascripts/discourse/node_modules/loader.js/dist/loader/loader.js",
-        ),
+        File.join(Rails.root, "frontend/discourse/node_modules/loader.js/dist/loader/loader.js"),
       )
   end
 
diff --git a/app/views/qunit/theme.html.erb b/app/views/qunit/theme.html.erb
index 0a498f9c6d8..6cb7d044f72 100644
--- a/app/views/qunit/theme.html.erb
+++ b/app/views/qunit/theme.html.erb
@@ -26,7 +26,7 @@
       <meta name="discourse/config/environment" content="<%=u discourse_config_environment(testing: true) %>" />
 
       <style>
-        <%= File.read("#{Rails.root}/app/assets/javascripts/discourse/node_modules/qunit/qunit/qunit.css").html_safe %>
+        <%= File.read("#{Rails.root}/frontend/discourse/node_modules/qunit/qunit/qunit.css").html_safe %>
       </style>
 
       <%= discourse_stylesheet_link_tag(:common, theme_id: nil) %>
diff --git a/bin/ember-cli b/bin/ember-cli
index 84f03f2a62d..f21049eb135 100755
--- a/bin/ember-cli
+++ b/bin/ember-cli
@@ -48,7 +48,7 @@ if ARGV.include?("-h") || ARGV.include?("--help")
   exec "pnpm ember #{command} --help"
 end
 
-args = ["--dir=app/assets/javascripts/discourse", "ember", command] + (ARGV - CUSTOM_ARGS)
+args = ["--dir=frontend/discourse", "ember", command] + (ARGV - CUSTOM_ARGS)
 
 if !args.include?("test") && !args.include?("build") && !args.include?("--proxy")
   args << "--proxy"
diff --git a/config/initializers/assets.rb b/config/initializers/assets.rb
index 1c7ccdcfa99..bc7092c941d 100644
--- a/config/initializers/assets.rb
+++ b/config/initializers/assets.rb
@@ -11,7 +11,7 @@ Rails.application.config.assets.version = "2-#{GlobalSetting.asset_url_salt}"
 # Add additional assets to the asset load path.
 Rails.application.config.assets.paths.push(
   "#{Rails.root}/public/javascripts",
-  "#{Rails.root}/app/assets/javascripts/discourse/dist/assets",
+  "#{Rails.root}/frontend/discourse/dist/assets",
 )
 
 Rails.application.config.assets.paths.push(
diff --git a/config/projections.json b/config/projections.json
index 7f49f292172..48beefeba15 100644
--- a/config/projections.json
+++ b/config/projections.json
@@ -1,29 +1,29 @@
 {
-  "app/assets/javascripts/discourse/components/*.js": {
+  "frontend/discourse/components/*.js": {
     "command": "dcomponent"
   },
-  "app/assets/javascripts/discourse/lib/*.js": {
+  "frontend/discourse/lib/*.js": {
     "command": "dlib"
   },
-  "app/assets/javascripts/discourse/routes/*.js": {
+  "frontend/discourse/routes/*.js": {
     "command": "droute"
   },
-  "app/assets/javascripts/discourse/controllers/*.js": {
+  "frontend/discourse/controllers/*.js": {
     "command": "dcontroller"
   },
-  "app/assets/javascripts/discourse/models/*.js": {
+  "frontend/discourse/models/*.js": {
     "command": "dmodel"
   },
-  "app/assets/javascripts/discourse/helpers/*.js": {
+  "frontend/discourse/helpers/*.js": {
     "command": "dhelper"
   },
-  "app/assets/javascripts/discourse/templates/*.hbs": {
+  "frontend/discourse/templates/*.hbs": {
     "command": "dtemplate"
   },
-  "app/assets/javascripts/discourse/templates/*.hbr": {
+  "frontend/discourse/templates/*.hbr": {
     "command": "dtemplate"
   },
-  "app/assets/javascripts/discourse/views/*.js": {
+  "frontend/discourse/views/*.js": {
     "command": "dview"
   },
   "app/serializers/*.rb": {
diff --git a/eslint.config.mjs b/eslint.config.mjs
index a4e31eb208d..c94b630fb9e 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -11,18 +11,14 @@ export default [
   },
   {
     ignores: [
-      "app/assets/javascripts/ember-addons/",
-      "lib/javascripts/locale/*",
-      "lib/javascripts/messageformat.js",
-      "lib/javascripts/messageformat-lookup.js",
       "plugins/**/lib/javascripts/locale",
       "plugins/discourse-math/public",
       "public/",
       "vendor/",
-      "app/assets/javascripts/discourse/tests/fixtures",
+      "frontend/discourse/tests/fixtures",
       "**/node_modules/",
       "spec/",
-      "app/assets/javascripts/discourse/dist/",
+      "frontend/discourse/dist/",
       "tmp/",
     ],
   },
diff --git a/jsconfig.json b/jsconfig.json
index a47e13cd029..aa9ca4c0cf9 100644
--- a/jsconfig.json
+++ b/jsconfig.json
@@ -8,31 +8,31 @@
     "allowJs": true,
     "paths": {
       "discourse/admin/*": [
-        "./app/assets/javascripts/discourse/admin/*"
+        "./frontend/discourse/admin/*"
       ],
       "discourse/*": [
-        "./app/assets/javascripts/discourse/app/*"
+        "./frontend/discourse/app/*"
       ],
       "discourse/tests/*": [
-        "./app/assets/javascripts/discourse/tests/*"
+        "./frontend/discourse/tests/*"
       ],
       "admin/*": [
-        "./app/assets/javascripts/discourse/admin/*"
+        "./frontend/discourse/admin/*"
       ],
       "pretty-text/*": [
-        "./app/assets/javascripts/pretty-text/addon/*"
+        "./frontend/pretty-text/addon/*"
       ],
       "select-kit/*": [
-        "./app/assets/javascripts/select-kit/addon/*"
+        "./frontend/select-kit/addon/*"
       ],
       "float-kit/*": [
-        "./app/assets/javascripts/float-kit/addon/*"
+        "./frontend/float-kit/addon/*"
       ],
       "truth-helpers/*": [
-        "./app/assets/javascripts/truth-helpers/addon/*"
+        "./frontend/truth-helpers/addon/*"
       ],
       "dialog-holder/*": [
-        "./app/assets/javascripts/dialog-holder/addon/*"
+        "./frontend/dialog-holder/addon/*"
       ],
       "discourse/plugins/automation/*": [
         "./plugins/automation/assets/javascripts/*",
@@ -213,15 +213,15 @@
     }
   },
   "include": [
-    "./app/assets/javascripts/discourse/admin",
-    "./app/assets/javascripts/discourse/app",
-    "./app/assets/javascripts/discourse/tests",
-    "./app/assets/javascripts/discourse/admin",
-    "./app/assets/javascripts/pretty-text/addon",
-    "./app/assets/javascripts/select-kit/addon",
-    "./app/assets/javascripts/float-kit/addon",
-    "./app/assets/javascripts/truth-helpers/addon",
-    "./app/assets/javascripts/dialog-holder/addon",
+    "./frontend/discourse/admin",
+    "./frontend/discourse/app",
+    "./frontend/discourse/tests",
+    "./frontend/discourse/admin",
+    "./frontend/pretty-text/addon",
+    "./frontend/select-kit/addon",
+    "./frontend/float-kit/addon",
+    "./frontend/truth-helpers/addon",
+    "./frontend/dialog-holder/addon",
     "./plugins/automation/assets/javascripts",
     "./plugins/automation/test/javascripts",
     "./plugins/chat/assets/javascripts",
@@ -312,6 +312,6 @@
     "./themes/horizon/test"
   ],
   "exclude": [
-    "app/assets/javascripts/discourse/tests/unit/utils/decorators-test.js"
+    "frontend/discourse/tests/unit/utils/decorators-test.js"
   ]
 }
diff --git a/lefthook.yml b/lefthook.yml
index 73886650005..b0f4df99553 100644
--- a/lefthook.yml
+++ b/lefthook.yml
@@ -20,11 +20,11 @@ pre-commit:
       run: pnpm pprettier --list-different {staged_files}
     eslint:
       glob: "*.{js,gjs}"
-      include: "app/assets/javascripts|plugins/.+?/assets/javascripts"
+      include: "frontend|plugins/.+?/assets/javascripts"
       run: pnpm eslint --quiet {staged_files}
     ember-template-lint:
       glob: "*.{hbs,gjs}"
-      include: "app/assets/javascripts|plugins/.+?/assets/javascripts"
+      include: "frontend|plugins/.+?/assets/javascripts"
       run: pnpm ember-template-lint {staged_files}
     yaml-syntax:
       glob: "*.{yaml,yml}"
@@ -48,11 +48,11 @@ fix-staged:
       run: pnpm pprettier --write {staged_files}
     eslint:
       glob: "*.{js,gjs}"
-      include: "app/assets/javascripts|plugins/.+?/assets/javascripts|themes"
+      include: "frontend|plugins/.+?/assets/javascripts|themes"
       run: pnpm eslint --fix {staged_files}
     ember-template-lint:
       glob: "*.{gjs,hbs}"
-      include: "app/assets/javascripts|plugins/.+?/assets/javascripts|themes"
+      include: "frontend|plugins/.+?/assets/javascripts|themes"
       run: pnpm ember-template-lint --fix {staged_files}
     stylelint:
       glob: "*.scss"
diff --git a/lib/asset_processor.rb b/lib/asset_processor.rb
index 5835e99b28a..06e8cadbb42 100644
--- a/lib/asset_processor.rb
+++ b/lib/asset_processor.rb
@@ -24,12 +24,7 @@ class AssetProcessor
   end
 
   def self.build_asset_processor
-    Discourse::Utils.execute_command(
-      "pnpm",
-      "-C=app/assets/javascripts/asset-processor",
-      "node",
-      "build.js",
-    )
+    Discourse::Utils.execute_command("pnpm", "-C=frontend/asset-processor", "node", "build.js")
   end
 
   def self.build_production_asset_processor
diff --git a/lib/autospec/rspec_runner.rb b/lib/autospec/rspec_runner.rb
index d77d01e4723..cdb684660b8 100644
--- a/lib/autospec/rspec_runner.rb
+++ b/lib/autospec/rspec_runner.rb
@@ -26,9 +26,7 @@ module Autospec
 
     watch(%r{\Aspec/fabricators/.+_fabricator\.rb\z}) { "spec" }
 
-    watch(%r{\Aapp/assets/javascripts/pretty-text/.*\.js\.es6\z}) do
-      "spec/components/pretty_text_spec.rb"
-    end
+    watch(%r{\Afrontend/pretty-text/.*\.js\.es6\z}) { "spec/components/pretty_text_spec.rb" }
     watch(%r{\Aplugins/.*/discourse-markdown/.*\.js\.es6\z}) do
       "spec/components/pretty_text_spec.rb"
     end
diff --git a/lib/discourse_plugin_registry.rb b/lib/discourse_plugin_registry.rb
index 5ac22fc414a..a17e1455332 100644
--- a/lib/discourse_plugin_registry.rb
+++ b/lib/discourse_plugin_registry.rb
@@ -250,9 +250,9 @@ class DiscoursePluginRegistry
   end
 
   VENDORED_CORE_PRETTY_TEXT_MAP = {
-    "moment.js" => "app/assets/javascripts/discourse/node_modules/moment/moment.js",
+    "moment.js" => "frontend/discourse/node_modules/moment/moment.js",
     "moment-timezone.js" =>
-      "app/assets/javascripts/discourse/node_modules/moment-timezone/builds/moment-timezone-with-data.js",
+      "frontend/discourse/node_modules/moment-timezone/builds/moment-timezone-with-data.js",
   }
 
   def self.core_asset_for_name(name)
diff --git a/lib/ember_cli.rb b/lib/ember_cli.rb
index 573920ab206..56f5dc5ecbe 100644
--- a/lib/ember_cli.rb
+++ b/lib/ember_cli.rb
@@ -5,7 +5,7 @@ class EmberCli < ActiveSupport::CurrentAttributes
   attribute :request_cache
 
   def self.dist_dir
-    "#{Rails.root}/app/assets/javascripts/discourse/dist"
+    "#{Rails.root}/frontend/discourse/dist"
   end
 
   def self.assets
diff --git a/lib/highlight_js.rb b/lib/highlight_js.rb
index 882f32fb6de..d535309976e 100644
--- a/lib/highlight_js.rb
+++ b/lib/highlight_js.rb
@@ -1,8 +1,7 @@
 # frozen_string_literal: true
 
 module HighlightJs
-  HIGHLIGHTJS_DIR =
-    "#{Rails.root}/app/assets/javascripts/discourse/node_modules/@highlightjs/cdn-assets/"
+  HIGHLIGHTJS_DIR = "#{Rails.root}/frontend/discourse/node_modules/@highlightjs/cdn-assets/"
   VERSION = 1 # bump to invalidate caches following core changes
 
   def self.languages
diff --git a/lib/js_locale_helper.rb b/lib/js_locale_helper.rb
index a655de4c838..d931d7ff07f 100644
--- a/lib/js_locale_helper.rb
+++ b/lib/js_locale_helper.rb
@@ -266,7 +266,7 @@ module JsLocaleHelper
       path = "#{Rails.root}/node_modules/@discourse/moment-timezone-names-translations/locales"
       type = :moment_js_timezones
     else
-      path = "#{Rails.root}/app/assets/javascripts/discourse/node_modules/moment/locale"
+      path = "#{Rails.root}/frontend/discourse/node_modules/moment/locale"
       type = :moment_js
     end
 
diff --git a/lib/presence_channel.rb b/lib/presence_channel.rb
index 929edb8bdf0..68f0113bfd0 100644
--- a/lib/presence_channel.rb
+++ b/lib/presence_channel.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 # The server-side implementation of PresenceChannels. See also {PresenceController}
-# and +app/assets/javascripts/discourse/app/services/presence.js+
+# and +frontend/discourse/app/services/presence.js+
 class PresenceChannel
   class NotFound < StandardError
   end
diff --git a/lib/pretty_text.rb b/lib/pretty_text.rb
index d378aa7f8b4..806b8b1ce68 100644
--- a/lib/pretty_text.rb
+++ b/lib/pretty_text.rb
@@ -82,9 +82,9 @@ module PrettyText
       ctx.attach("__helpers.#{method}", PrettyText::Helpers.method(method))
     end
 
-    root_path = "#{Rails.root}/app/assets/javascripts"
-    d_node_modules = "#{Rails.root}/app/assets/javascripts/discourse/node_modules"
-    md_node_modules = "#{Rails.root}/app/assets/javascripts/discourse-markdown-it/node_modules"
+    root_path = "#{Rails.root}/frontend"
+    d_node_modules = "#{Rails.root}/frontend/discourse/node_modules"
+    md_node_modules = "#{Rails.root}/frontend/discourse-markdown-it/node_modules"
     ctx.load("#{d_node_modules}/loader.js/dist/loader/loader.js")
     ctx.load("#{md_node_modules}/markdown-it/dist/markdown-it.js")
     ctx.load("#{md_node_modules}/xss/dist/xss.js")
diff --git a/lib/tasks/docker.rake b/lib/tasks/docker.rake
index 2d7835eb87f..206b00f460e 100644
--- a/lib/tasks/docker.rake
+++ b/lib/tasks/docker.rake
@@ -183,7 +183,7 @@ task "docker:test" do
       else
         @good &&= run_or_fail("bundle exec rake plugin:update_all") unless ENV["SKIP_PLUGINS"]
         @good &&= run_or_fail("bundle exec rubocop") unless ENV["SKIP_CORE"]
-        @good &&= run_or_fail("pnpm eslint app/assets/javascripts") unless ENV["SKIP_CORE"]
+        @good &&= run_or_fail("pnpm eslint frontend") unless ENV["SKIP_CORE"]
         @good &&=
           run_or_fail(
             "pnpm eslint --ext .js,.js.es6 --no-error-on-unmatched-pattern plugins",
@@ -202,7 +202,7 @@ task "docker:test" do
           puts "Listing prettier offenses in core:"
           @good &&=
             run_or_fail(
-              'pnpm pprettier --list-different "app/assets/stylesheets/**/*.scss" "app/assets/javascripts/**/*.js"',
+              'pnpm pprettier --list-different "app/assets/stylesheets/**/*.scss" "frontend/**/*.js"',
             )
         end
 
diff --git a/lib/tasks/javascript.rake b/lib/tasks/javascript.rake
index d11fe6d0e5a..222f5d69cda 100644
--- a/lib/tasks/javascript.rake
+++ b/lib/tasks/javascript.rake
@@ -7,7 +7,7 @@ def write_template(path, task_name, template)
   JS
 
   basename = File.basename(path)
-  output_path = "#{Rails.root}/app/assets/javascripts/#{path}"
+  output_path = "#{Rails.root}/frontend/#{path}"
 
   File.write(output_path, "#{header}\n\n#{template}")
   puts "#{basename} created"
diff --git a/lib/tasks/qunit.rake b/lib/tasks/qunit.rake
index 93471045c92..c546c09e770 100644
--- a/lib/tasks/qunit.rake
+++ b/lib/tasks/qunit.rake
@@ -113,13 +113,7 @@ task "qunit:test", %i[qunit_path filter] do |_, args|
       # Bypass `ember test` - it only works properly for the `/tests` path.
       # We have to trigger a `build` manually so that JS is available for rails to serve.
       if !reuse_build
-        system(
-          "pnpm",
-          "ember",
-          "build",
-          chdir: "#{Rails.root}/app/assets/javascripts/discourse",
-          exception: true,
-        )
+        system("pnpm", "ember", "build", chdir: "#{Rails.root}/frontend/discourse", exception: true)
       end
 
       env["THEME_TEST_PAGES"] = if ENV["THEME_IDS"]
@@ -144,7 +138,7 @@ task "qunit:test", %i[qunit_path filter] do |_, args|
 
     # Print out all env for debugging purposes
     p env
-    system(env, *cmd, chdir: "#{Rails.root}/app/assets/javascripts/discourse")
+    system(env, *cmd, chdir: "#{Rails.root}/frontend/discourse")
 
     success &&= $?.success?
   ensure
diff --git a/package.json b/package.json
index 58510038c65..208ce0406d9 100644
--- a/package.json
+++ b/package.json
@@ -37,17 +37,17 @@
     "lint:fix": "concurrently \"pnpm:lint:*:fix\" --names \"fix:\"",
     "lint:css": "pnpm stylelint 'app/assets/stylesheets/**/*.scss' $(script/list_bundled_plugins '/assets/stylesheets/**/*.scss') 'themes/**/*.scss'",
     "lint:css:fix": "pnpm stylelint --fix 'app/assets/stylesheets/**/*.scss' $(script/list_bundled_plugins '/assets/stylesheets/**/*.scss') 'themes/**/*.scss'",
-    "lint:js": "eslint ./app/assets/javascripts $(script/list_bundled_plugins) ./themes --cache --no-error-on-unmatched-pattern",
-    "lint:js:fix": "eslint --fix ./app/assets/javascripts $(script/list_bundled_plugins) ./themes --no-error-on-unmatched-pattern",
-    "lint:hbs": "ember-template-lint 'app/assets/javascripts/**/*.{gjs,hbs}' 'plugins/*/assets/javascripts/**/*.{gjs,hbs}' 'plugins/*/admin/assets/javascripts/**/*.{gjs,hbs}' 'themes/**/*.{gjs,hbs}'",
-    "lint:hbs:fix": "ember-template-lint 'app/assets/javascripts/**/*.{gjs,hbs}' 'plugins/*/assets/javascripts/**/*.{gjs,hbs}' 'plugins/*/admin/assets/javascripts/**/*.{gjs,hbs}' 'themes/**/*.{gjs,hbs}' --fix",
-    "lint:prettier": "pnpm pprettier --list-different 'app/assets/stylesheets/**/*.scss' 'app/assets/javascripts/**/*.{js,gjs,hbs,css}' $(script/list_bundled_plugins '/assets/stylesheets/**/*.scss') $(script/list_bundled_plugins '/{assets,admin/assets,test}/javascripts/**/*.{js,gjs,hbs}') 'themes/**/*.{js,gjs,hbs,scss}'",
-    "lint:prettier:fix": "pnpm prettier -w --no-error-on-unmatched-pattern 'app/assets/stylesheets/**/*.scss' 'app/assets/javascripts/**/*.{js,gjs,hbs,css}' $(script/list_bundled_plugins '/assets/stylesheets/**/*.scss') $(script/list_bundled_plugins '/{assets,admin/assets,test}/javascripts/**/*.{js,gjs,hbs}') 'themes/**/*.{js,gjs,hbs,scss}'",
+    "lint:js": "eslint ./frontend $(script/list_bundled_plugins) ./themes --cache --no-error-on-unmatched-pattern",
+    "lint:js:fix": "eslint --fix ./frontend $(script/list_bundled_plugins) ./themes --no-error-on-unmatched-pattern",
+    "lint:hbs": "ember-template-lint 'frontend/**/*.{gjs,hbs}' 'plugins/*/assets/javascripts/**/*.{gjs,hbs}' 'plugins/*/admin/assets/javascripts/**/*.{gjs,hbs}' 'themes/**/*.{gjs,hbs}'",
+    "lint:hbs:fix": "ember-template-lint 'frontend/**/*.{gjs,hbs}' 'plugins/*/assets/javascripts/**/*.{gjs,hbs}' 'plugins/*/admin/assets/javascripts/**/*.{gjs,hbs}' 'themes/**/*.{gjs,hbs}' --fix",
+    "lint:prettier": "pnpm pprettier --list-different 'app/assets/stylesheets/**/*.scss' 'frontend/**/*.{js,gjs,hbs,css}' $(script/list_bundled_plugins '/assets/stylesheets/**/*.scss') $(script/list_bundled_plugins '/{assets,admin/assets,test}/javascripts/**/*.{js,gjs,hbs}') 'themes/**/*.{js,gjs,hbs,scss}'",
+    "lint:prettier:fix": "pnpm prettier -w --no-error-on-unmatched-pattern 'app/assets/stylesheets/**/*.scss' 'frontend/**/*.{js,gjs,hbs,css}' $(script/list_bundled_plugins '/assets/stylesheets/**/*.scss') $(script/list_bundled_plugins '/{assets,admin/assets,test}/javascripts/**/*.{js,gjs,hbs}') 'themes/**/*.{js,gjs,hbs,scss}'",
     "lint:glint": "ember-tsc -p jsconfig.json --noEmit",
     "lttf:ignore": "lint-to-the-future ignore",
     "lttf:output": "lint-to-the-future output -o ./lint-progress/",
     "lint-progress": "pnpm lttf:output && npx html-pages ./lint-progress --no-cache",
-    "ember": "pnpm --dir=app/assets/javascripts/discourse ember",
+    "ember": "pnpm --dir=frontend/discourse ember",
     "playwright-install": "playwright install --no-shell chromium"
   },
   "engines": {
diff --git a/plugins/discourse-assign/test/javascripts/acceptance/assign-enabled-test.js b/plugins/discourse-assign/test/javascripts/acceptance/assign-enabled-test.js
index 81238e1ffe8..c8e6e901355 100644
--- a/plugins/discourse-assign/test/javascripts/acceptance/assign-enabled-test.js
+++ b/plugins/discourse-assign/test/javascripts/acceptance/assign-enabled-test.js
@@ -322,7 +322,7 @@ acceptance(
 
         // usually this is done automatically by this pretender but we
         // have to do it manually here because we are overriding the
-        // pretender see app/assets/javascripts/discourse/tests/helpers/create-pretender.js
+        // pretender see frontend/discourse/tests/helpers/create-pretender.js
         json.user.can_edit = true;
 
         return helper.response(200, json);
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 1e2cc5ae830..bb970ece466 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -107,7 +107,7 @@ importers:
         specifier: 5.6.x
         version: 5.6.3
 
-  app/assets/javascripts/asset-processor:
+  frontend/asset-processor:
     dependencies:
       '@babel/core':
         specifier: ^7.28.4
@@ -204,7 +204,7 @@ importers:
         specifier: ^3.2.4
         version: 3.2.4(@types/node@24.9.1)(jsdom@25.0.1)(terser@5.44.0)
 
-  app/assets/javascripts/custom-proxy:
+  frontend/custom-proxy:
     devDependencies:
       clean-base-url:
         specifier: ^1.0.0
@@ -225,9 +225,9 @@ importers:
         specifier: ^3.3.2
         version: 3.3.2
 
-  app/assets/javascripts/deprecation-silencer: {}
+  frontend/deprecation-silencer: {}
 
-  app/assets/javascripts/dialog-holder:
+  frontend/dialog-holder:
     dependencies:
       a11y-dialog:
         specifier: 8.1.4
@@ -261,7 +261,7 @@ importers:
         specifier: 5.99.9
         version: 5.99.9(@swc/core@1.13.5)(esbuild@0.25.11)
 
-  app/assets/javascripts/discourse:
+  frontend/discourse:
     dependencies:
       '@faker-js/faker':
         specifier: ^10.1.0
@@ -673,7 +673,7 @@ importers:
         specifier: ^1.0.15
         version: 1.0.15
 
-  app/assets/javascripts/discourse-i18n:
+  frontend/discourse-i18n:
     dependencies:
       '@embroider/addon-shim':
         specifier: ^1.9.0
@@ -682,7 +682,7 @@ importers:
         specifier: ^7.4.0
         version: 7.4.0
 
-  app/assets/javascripts/discourse-markdown-it:
+  frontend/discourse-markdown-it:
     dependencies:
       '@embroider/addon-shim':
         specifier: ^1.9.0
@@ -706,7 +706,7 @@ importers:
         specifier: ^1.0.15
         version: 1.0.15
 
-  app/assets/javascripts/discourse-plugins:
+  frontend/discourse-plugins:
     dependencies:
       '@babel/core':
         specifier: ^7.28.4
@@ -737,7 +737,7 @@ importers:
         specifier: 5.99.9
         version: 5.99.9(@swc/core@1.13.5)(esbuild@0.25.11)
 
-  app/assets/javascripts/discourse-widget-hbs:
+  frontend/discourse-widget-hbs:
     dependencies:
       '@babel/core':
         specifier: ^7.28.4
@@ -801,9 +801,9 @@ importers:
         specifier: 5.99.9
         version: 5.99.9(@swc/core@1.13.5)(esbuild@0.25.11)
 
-  app/assets/javascripts/ember-cli-progress-ci: {}
+  frontend/ember-cli-progress-ci: {}
 
-  app/assets/javascripts/float-kit:
+  frontend/float-kit:
     dependencies:
       '@babel/core':
         specifier: ^7.28.4
@@ -888,7 +888,7 @@ importers:
         specifier: 5.99.9
         version: 5.99.9(@swc/core@1.13.5)(esbuild@0.25.11)
 
-  app/assets/javascripts/pretty-text:
+  frontend/pretty-text:
     dependencies:
       '@babel/core':
         specifier: ^7.28.4
@@ -964,7 +964,7 @@ importers:
         specifier: 5.99.9
         version: 5.99.9(@swc/core@1.13.5)(esbuild@0.25.11)
 
-  app/assets/javascripts/select-kit:
+  frontend/select-kit:
     dependencies:
       '@babel/core':
         specifier: ^7.28.4
@@ -1058,7 +1058,7 @@ importers:
         specifier: 5.99.9
         version: 5.99.9(@swc/core@1.13.5)(esbuild@0.25.11)
 
-  app/assets/javascripts/truth-helpers:
+  frontend/truth-helpers:
     dependencies:
       '@embroider/addon-shim':
         specifier: ^1.9.0
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index bc62ab6b42b..fc3f33dd7b2 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -1,15 +1,15 @@
 packages:
-- "app/assets/javascripts/custom-proxy"
-- "app/assets/javascripts/deprecation-silencer"
-- "app/assets/javascripts/dialog-holder"
-- "app/assets/javascripts/discourse"
-- "app/assets/javascripts/discourse-i18n"
-- "app/assets/javascripts/discourse-markdown-it"
-- "app/assets/javascripts/discourse-plugins"
-- "app/assets/javascripts/discourse-widget-hbs"
-- "app/assets/javascripts/ember-cli-progress-ci"
-- "app/assets/javascripts/float-kit"
-- "app/assets/javascripts/pretty-text"
-- "app/assets/javascripts/select-kit"
-- "app/assets/javascripts/asset-processor"
-- "app/assets/javascripts/truth-helpers"
+- "frontend/custom-proxy"
+- "frontend/deprecation-silencer"
+- "frontend/dialog-holder"
+- "frontend/discourse"
+- "frontend/discourse-i18n"
+- "frontend/discourse-markdown-it"
+- "frontend/discourse-plugins"
+- "frontend/discourse-widget-hbs"
+- "frontend/ember-cli-progress-ci"
+- "frontend/float-kit"
+- "frontend/pretty-text"
+- "frontend/select-kit"
+- "frontend/asset-processor"
+- "frontend/truth-helpers"
diff --git a/script/assemble_ember_build.rb b/script/assemble_ember_build.rb
index aafd74a993e..e44677e79b4 100755
--- a/script/assemble_ember_build.rb
+++ b/script/assemble_ember_build.rb
@@ -15,9 +15,9 @@ DOWNLOAD_TEMP_FILE = "#{__dir__}/../tmp/assets.tar.gz"
 
 PRE_BUILD_ROOT = "https://get.discourse.org/discourse-assets"
 
-JS_SOURCE_PATHS = %w[app/assets/javascripts package.json pnpm-lock.yaml]
+JS_SOURCE_PATHS = %w[frontend package.json pnpm-lock.yaml]
 
-EMBER_APP_DIR = "app/assets/javascripts/discourse"
+EMBER_APP_DIR = "frontend/discourse"
 BUILD_INFO_FILE = "#{EMBER_APP_DIR}/dist/BUILD_INFO.json"
 
 Dir.chdir("#{__dir__}/..")
diff --git a/script/build_jsconfig.rb b/script/build_jsconfig.rb
index 5fe113cf027..2cb879e10b5 100755
--- a/script/build_jsconfig.rb
+++ b/script/build_jsconfig.rb
@@ -7,15 +7,15 @@ require "json"
 Dir.chdir("#{__dir__}/..") # rubocop:disable Discourse/NoChdir because this is not part of the app
 
 CORE_NAMESPACES = {
-  "discourse/admin/*" => ["app/assets/javascripts/discourse/admin"],
-  "discourse/*" => ["app/assets/javascripts/discourse/app"],
-  "discourse/tests/*" => ["app/assets/javascripts/discourse/tests"],
-  "admin/*" => ["app/assets/javascripts/discourse/admin"], # TODO: remove once all core code is migrated to new import path
-  "pretty-text/*" => ["app/assets/javascripts/pretty-text/addon"],
-  "select-kit/*" => ["app/assets/javascripts/select-kit/addon"],
-  "float-kit/*" => ["app/assets/javascripts/float-kit/addon"],
-  "truth-helpers/*" => ["app/assets/javascripts/truth-helpers/addon"],
-  "dialog-holder/*" => ["app/assets/javascripts/dialog-holder/addon"],
+  "discourse/admin/*" => ["frontend/discourse/admin"],
+  "discourse/*" => ["frontend/discourse/app"],
+  "discourse/tests/*" => ["frontend/discourse/tests"],
+  "admin/*" => ["frontend/discourse/admin"], # TODO: remove once all core code is migrated to new import path
+  "pretty-text/*" => ["frontend/pretty-text/addon"],
+  "select-kit/*" => ["frontend/select-kit/addon"],
+  "float-kit/*" => ["frontend/float-kit/addon"],
+  "truth-helpers/*" => ["frontend/truth-helpers/addon"],
+  "dialog-holder/*" => ["frontend/dialog-holder/addon"],
 }
 
 def relative(from, to)
@@ -42,7 +42,7 @@ def write_config(package_dir, extras: {})
     },
     "include" => namespaces.flat_map { |ns, paths| paths.map { |p| relative(package_dir, p) } },
     "exclude" => [
-      "app/assets/javascripts/discourse/tests/unit/utils/decorators-test.js", # Native class decorators - unsupported by ts/glint
+      "frontend/discourse/tests/unit/utils/decorators-test.js", # Native class decorators - unsupported by ts/glint
     ],
   }
 
diff --git a/script/check_reproducible_assets.rb b/script/check_reproducible_assets.rb
index b61d012bae0..9f14213c377 100755
--- a/script/check_reproducible_assets.rb
+++ b/script/check_reproducible_assets.rb
@@ -7,7 +7,7 @@
 
 require "digest"
 
-DIST_DIR = File.expand_path("#{__dir__}/../app/assets/javascripts/discourse/dist")
+DIST_DIR = File.expand_path("#{__dir__}/../frontend/discourse/dist")
 
 def collect_asset_info
   files =
diff --git a/script/publish_built_assets.rb b/script/publish_built_assets.rb
index 5adea77dbd7..29c785356b4 100755
--- a/script/publish_built_assets.rb
+++ b/script/publish_built_assets.rb
@@ -26,7 +26,7 @@ end
 
 common_env = { "DISCOURSE_DOWNLOAD_PRE_BUILT_ASSETS" => "0", "LOAD_PLUGINS" => "0" }
 
-Dir.chdir("#{__dir__}/../app/assets/javascripts/discourse")
+Dir.chdir("#{__dir__}/../frontend/discourse")
 FileUtils.rm_rf("dist")
 
 system({ **common_env, "EMBER_ENV" => "production" }, "#{__dir__}/assemble_ember_build.rb")
diff --git a/spec/integrity/coding_style_spec.rb b/spec/integrity/coding_style_spec.rb
index f22851a4f11..45e7d259e76 100644
--- a/spec/integrity/coding_style_spec.rb
+++ b/spec/integrity/coding_style_spec.rb
@@ -48,8 +48,8 @@ RSpec.describe "Coding style" do
 
   describe "non-colocated component templates" do
     {
-      "discourse" => "app/assets/javascripts/discourse/app/templates/components",
-      "admin" => "app/assets/javascripts/admin/addon/templates/components",
+      "discourse" => "frontend/discourse/app/templates/components",
+      "admin" => "frontend/admin/addon/templates/components",
       "chat/discourse" => "plugins/chat/assets/javascripts/discourse/templates/components",
       "chat/admin" => "plugins/chat/assets/javascripts/admin/templates/components",
       "styleguide" => "plugins/styleguide/assets/javascripts/discourse/templates/components",
diff --git a/spec/integrity/js_constants_spec.rb b/spec/integrity/js_constants_spec.rb
index 559f2c45337..c1a0e7e5a18 100644
--- a/spec/integrity/js_constants_spec.rb
+++ b/spec/integrity/js_constants_spec.rb
@@ -5,7 +5,7 @@ RSpec.describe "constants match ruby" do
 
   def parse(file)
     # mini racer doesn't handle JS modules so we'll do this hack
-    source = File.read("#{Rails.root}/app/assets/javascripts/#{file}")
+    source = File.read("#{Rails.root}/frontend/#{file}")
     source.gsub!(/^export */, "")
     ctx.eval(source)
   end
diff --git a/spec/lib/js_locale_helper_spec.rb b/spec/lib/js_locale_helper_spec.rb
index 574b6e91c3b..3954cfb8c10 100644
--- a/spec/lib/js_locale_helper_spec.rb
+++ b/spec/lib/js_locale_helper_spec.rb
@@ -2,7 +2,7 @@
 
 RSpec.describe JsLocaleHelper do
   let(:v8_ctx) do
-    discourse_node_modules = "#{Rails.root}/app/assets/javascripts/discourse/node_modules"
+    discourse_node_modules = "#{Rails.root}/frontend/discourse/node_modules"
     mf_runtime = "#{discourse_node_modules}/@messageformat/runtime"
     processor = AssetProcessor.new
     ctx = MiniRacer::Context.new
@@ -13,7 +13,7 @@ RSpec.describe JsLocaleHelper do
       "@messageformat/runtime": "#{mf_runtime}/esm/runtime.js",
       "@messageformat/runtime/lib/cardinals": "#{mf_runtime}/esm/cardinals.js",
       "make-plural/cardinals": "#{discourse_node_modules}/make-plural/cardinals.mjs",
-      "discourse-i18n": "#{Rails.root}/app/assets/javascripts/discourse-i18n/src/index.js",
+      "discourse-i18n": "#{Rails.root}/frontend/discourse-i18n/src/index.js",
     }.each do |module_name, path|
       ctx.eval(processor.perform(File.read(path), "", module_name.to_s))
     end
diff --git a/spec/lib/plugin/instance_spec.rb b/spec/lib/plugin/instance_spec.rb
index 970d2160434..2d5b69fb861 100644
--- a/spec/lib/plugin/instance_spec.rb
+++ b/spec/lib/plugin/instance_spec.rb
@@ -350,7 +350,7 @@ TEXT
       plugin.send :register_assets!
 
       expect(DiscoursePluginRegistry.vendored_core_pretty_text.first).to eq(
-        "app/assets/javascripts/discourse/node_modules/moment/moment.js",
+        "frontend/discourse/node_modules/moment/moment.js",
       )
     end
   end
@@ -577,10 +577,7 @@ TEXT
 
       expect(locale[:fallbackLocale]).to eq("pt_BR")
       expect(locale[:moment_js]).to eq(
-        [
-          "pt-br",
-          "#{Rails.root}/app/assets/javascripts/discourse/node_modules/moment/locale/pt-br.js",
-        ],
+        ["pt-br", "#{Rails.root}/frontend/discourse/node_modules/moment/locale/pt-br.js"],
       )
       expect(locale[:moment_js_timezones]).to eq(
         [
@@ -601,7 +598,7 @@ TEXT
 
       expect(locale[:fallbackLocale]).to be_nil
       expect(locale[:moment_js]).to eq(
-        ["tlh", "#{Rails.root}/app/assets/javascripts/discourse/node_modules/moment/locale/tlh.js"],
+        ["tlh", "#{Rails.root}/frontend/discourse/node_modules/moment/locale/tlh.js"],
       )
       expect(locale[:plural]).to eq(plural.with_indifferent_access)