diff --git a/app/controllers/admin/base_controller.rb b/app/controllers/admin/base_controller.rb
index a71bb61298..4b5afbe157 100644
--- a/app/controllers/admin/base_controller.rb
+++ b/app/controllers/admin/base_controller.rb
@@ -7,7 +7,6 @@ module Admin
 
     layout 'admin'
 
-    before_action :set_pack
     before_action :set_body_classes
     before_action :set_cache_headers
 
@@ -19,10 +18,6 @@ module Admin
       @body_classes = 'admin'
     end
 
-    def set_pack
-      use_pack 'admin'
-    end
-
     def set_cache_headers
       response.cache_control.replace(private: true, no_store: true)
     end
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index cf953fcf2c..bd152dbb66 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -165,10 +165,7 @@ class ApplicationController < ActionController::Base
 
   def respond_with_error(code)
     respond_to do |format|
-      format.any do
-        use_pack 'error'
-        render "errors/#{code}", layout: 'error', status: code, formats: [:html]
-      end
+      format.any  { render "errors/#{code}", layout: 'error', status: code, formats: [:html] }
       format.json { render json: { error: Rack::Utils::HTTP_STATUS_CODES[code] }, status: code }
     end
   end
@@ -177,10 +174,7 @@ class ApplicationController < ActionController::Base
     return unless self_destruct?
 
     respond_to do |format|
-      format.any do
-        use_pack 'error'
-        render 'errors/self_destruct', layout: 'auth', status: 410, formats: [:html]
-      end
+      format.any  { render 'errors/self_destruct', layout: 'auth', status: 410, formats: [:html] }
       format.json { render json: { error: Rack::Utils::HTTP_STATUS_CODES[410] }, status: 410 }
     end
   end
diff --git a/app/controllers/auth/challenges_controller.rb b/app/controllers/auth/challenges_controller.rb
index 1e585de189..7ede420b51 100644
--- a/app/controllers/auth/challenges_controller.rb
+++ b/app/controllers/auth/challenges_controller.rb
@@ -5,7 +5,6 @@ class Auth::ChallengesController < ApplicationController
 
   layout 'auth'
 
-  before_action :set_pack
   before_action :authenticate_user!
 
   skip_before_action :check_self_destruct!
@@ -21,10 +20,4 @@ class Auth::ChallengesController < ApplicationController
       render_challenge
     end
   end
-
-  private
-
-  def set_pack
-    use_pack 'auth'
-  end
 end
diff --git a/app/controllers/auth/confirmations_controller.rb b/app/controllers/auth/confirmations_controller.rb
index 8b8a27d260..7ca7be5f8e 100644
--- a/app/controllers/auth/confirmations_controller.rb
+++ b/app/controllers/auth/confirmations_controller.rb
@@ -6,7 +6,6 @@ class Auth::ConfirmationsController < Devise::ConfirmationsController
   layout 'auth'
 
   before_action :set_body_classes
-  before_action :set_pack
   before_action :set_confirmation_user!, only: [:show, :confirm_captcha]
   before_action :redirect_confirmed_user, if: :signed_in_confirmed_user?
 
@@ -66,10 +65,6 @@ class Auth::ConfirmationsController < Devise::ConfirmationsController
     @confirmation_user.nil? || @confirmation_user.confirmed?
   end
 
-  def set_pack
-    use_pack 'auth'
-  end
-
   def redirect_confirmed_user
     redirect_to(current_user.approved? ? root_path : edit_user_registration_path)
   end
diff --git a/app/controllers/auth/passwords_controller.rb b/app/controllers/auth/passwords_controller.rb
index f0d47bf774..de001f062b 100644
--- a/app/controllers/auth/passwords_controller.rb
+++ b/app/controllers/auth/passwords_controller.rb
@@ -3,7 +3,6 @@
 class Auth::PasswordsController < Devise::PasswordsController
   skip_before_action :check_self_destruct!
   before_action :redirect_invalid_reset_token, only: :edit, unless: :reset_password_token_is_valid?
-  before_action :set_pack
   before_action :set_body_classes
 
   layout 'auth'
@@ -32,8 +31,4 @@ class Auth::PasswordsController < Devise::PasswordsController
   def reset_password_token_is_valid?
     resource_class.with_reset_password_token(params[:reset_password_token]).present?
   end
-
-  def set_pack
-    use_pack 'auth'
-  end
 end
diff --git a/app/controllers/auth/registrations_controller.rb b/app/controllers/auth/registrations_controller.rb
index 838869b2ee..acfc0af0d9 100644
--- a/app/controllers/auth/registrations_controller.rb
+++ b/app/controllers/auth/registrations_controller.rb
@@ -9,7 +9,6 @@ class Auth::RegistrationsController < Devise::RegistrationsController
   before_action :set_invite, only: [:new, :create]
   before_action :check_enabled_registrations, only: [:new, :create]
   before_action :configure_sign_up_params, only: [:create]
-  before_action :set_pack
   before_action :set_sessions, only: [:edit, :update]
   before_action :set_strikes, only: [:edit, :update]
   before_action :set_body_classes, only: [:new, :create, :edit, :update]
@@ -97,10 +96,6 @@ class Auth::RegistrationsController < Devise::RegistrationsController
 
   private
 
-  def set_pack
-    use_pack %w(edit update).include?(action_name) ? 'admin' : 'auth'
-  end
-
   def set_body_classes
     @body_classes = %w(edit update).include?(action_name) ? 'admin' : 'lighter'
   end
diff --git a/app/controllers/auth/sessions_controller.rb b/app/controllers/auth/sessions_controller.rb
index 67d369b859..6ed7b2baac 100644
--- a/app/controllers/auth/sessions_controller.rb
+++ b/app/controllers/auth/sessions_controller.rb
@@ -12,7 +12,6 @@ class Auth::SessionsController < Devise::SessionsController
   skip_before_action :require_functional!
   skip_before_action :update_user_sign_in
 
-  prepend_before_action :set_pack
   prepend_before_action :check_suspicious!, only: [:create]
 
   include Auth::TwoFactorAuthenticationConcern
@@ -104,10 +103,6 @@ class Auth::SessionsController < Devise::SessionsController
 
   private
 
-  def set_pack
-    use_pack 'auth'
-  end
-
   def set_body_classes
     @body_classes = 'lighter'
   end
diff --git a/app/controllers/auth/setup_controller.rb b/app/controllers/auth/setup_controller.rb
index 8edca4d01b..40916d2887 100644
--- a/app/controllers/auth/setup_controller.rb
+++ b/app/controllers/auth/setup_controller.rb
@@ -3,7 +3,6 @@
 class Auth::SetupController < ApplicationController
   layout 'auth'
 
-  before_action :set_pack
   before_action :authenticate_user!
   before_action :require_unconfirmed_or_pending!
   before_action :set_body_classes
@@ -43,8 +42,4 @@ class Auth::SetupController < ApplicationController
   def user_params
     params.require(:user).permit(:email)
   end
-
-  def set_pack
-    use_pack 'sign_up'
-  end
 end
diff --git a/app/controllers/concerns/auth/two_factor_authentication_concern.rb b/app/controllers/concerns/auth/two_factor_authentication_concern.rb
index edcdd2990f..404164751a 100644
--- a/app/controllers/concerns/auth/two_factor_authentication_concern.rb
+++ b/app/controllers/concerns/auth/two_factor_authentication_concern.rb
@@ -83,8 +83,6 @@ module Auth::TwoFactorAuthenticationConcern
   def prompt_for_two_factor(user)
     register_attempt_in_session(user)
 
-    use_pack 'auth'
-
     @body_classes     = 'lighter'
     @webauthn_enabled = user.webauthn_enabled?
     @scheme_type      = if user.webauthn_enabled? && user_params[:otp_attempt].blank?
diff --git a/app/controllers/concerns/theming_concern.rb b/app/controllers/concerns/theming_concern.rb
index 7da04e1531..ebdaf54c05 100644
--- a/app/controllers/concerns/theming_concern.rb
+++ b/app/controllers/concerns/theming_concern.rb
@@ -3,19 +3,17 @@
 module ThemingConcern
   extend ActiveSupport::Concern
 
-  def use_pack(pack_name)
-    @theme = resolve_pack(Themes.instance.flavour(current_flavour), pack_name)
-  end
-
   private
 
   def current_flavour
-    [current_user&.setting_flavour, Setting.flavour, 'glitch', 'vanilla'].find { |flavour| Themes.instance.flavours.include?(flavour) }
+    @current_flavour ||= [current_user&.setting_flavour, Setting.flavour, 'glitch', 'vanilla'].find { |flavour| Themes.instance.flavours.include?(flavour) }
   end
 
   def current_skin
-    skins = Themes.instance.skins_for(current_flavour)
-    [current_user&.setting_skin, Setting.skin, 'default'].find { |skin| skins.include?(skin) }
+    @current_skin ||= begin
+      skins = Themes.instance.skins_for(current_flavour)
+      [current_user&.setting_skin, Setting.skin, 'default'].find { |skin| skins.include?(skin) }
+    end
   end
 
   def current_theme
@@ -23,25 +21,4 @@ module ThemingConcern
     # for the sole purpose of pointing to the appropriate stylesheet pack
     "skins/#{current_flavour}/#{current_skin}"
   end
-
-  def resolve_pack(data, pack_name)
-    pack_data = {
-      flavour: data['name'],
-      pack: nil,
-      preload: nil,
-      supported_locales: data['locales'],
-    }
-    return pack_data unless data['pack'].is_a?(Hash) && data['pack'][pack_name].present?
-
-    pack_data[:pack] = pack_name
-    return pack_data unless data['pack'][pack_name].is_a?(Hash)
-
-    pack_data[:pack] = nil unless data['pack'][pack_name]['filename']
-
-    preloads = data['pack'][pack_name]['preload']
-    pack_data[:preload] = [preloads] if preloads.is_a?(String)
-    pack_data[:preload] = preloads if preloads.is_a?(Array)
-
-    pack_data
-  end
 end
diff --git a/app/controllers/concerns/web_app_controller_concern.rb b/app/controllers/concerns/web_app_controller_concern.rb
index d20643e66c..24cccf1667 100644
--- a/app/controllers/concerns/web_app_controller_concern.rb
+++ b/app/controllers/concerns/web_app_controller_concern.rb
@@ -7,7 +7,6 @@ module WebAppControllerConcern
     vary_by 'Accept, Accept-Language, Cookie'
 
     before_action :redirect_unauthenticated_to_permalinks!
-    before_action :set_pack
     before_action :set_app_body_class
   end
 
@@ -37,8 +36,4 @@ module WebAppControllerConcern
       end
     end
   end
-
-  def set_pack
-    use_pack 'application'
-  end
 end
diff --git a/app/controllers/disputes/base_controller.rb b/app/controllers/disputes/base_controller.rb
index f51f44c620..1054f3db80 100644
--- a/app/controllers/disputes/base_controller.rb
+++ b/app/controllers/disputes/base_controller.rb
@@ -9,15 +9,10 @@ class Disputes::BaseController < ApplicationController
 
   before_action :set_body_classes
   before_action :authenticate_user!
-  before_action :set_pack
   before_action :set_cache_headers
 
   private
 
-  def set_pack
-    use_pack 'admin'
-  end
-
   def set_body_classes
     @body_classes = 'admin'
   end
diff --git a/app/controllers/filters/statuses_controller.rb b/app/controllers/filters/statuses_controller.rb
index 97206c7eda..94993f938b 100644
--- a/app/controllers/filters/statuses_controller.rb
+++ b/app/controllers/filters/statuses_controller.rb
@@ -6,7 +6,6 @@ class Filters::StatusesController < ApplicationController
   before_action :authenticate_user!
   before_action :set_filter
   before_action :set_status_filters
-  before_action :set_pack
   before_action :set_body_classes
   before_action :set_cache_headers
 
@@ -27,10 +26,6 @@ class Filters::StatusesController < ApplicationController
 
   private
 
-  def set_pack
-    use_pack 'admin'
-  end
-
   def set_filter
     @filter = current_account.custom_filters.find(params[:filter_id])
   end
diff --git a/app/controllers/filters_controller.rb b/app/controllers/filters_controller.rb
index 1b19269b23..bd9964426b 100644
--- a/app/controllers/filters_controller.rb
+++ b/app/controllers/filters_controller.rb
@@ -5,7 +5,6 @@ class FiltersController < ApplicationController
 
   before_action :authenticate_user!
   before_action :set_filter, only: [:edit, :update, :destroy]
-  before_action :set_pack
   before_action :set_body_classes
   before_action :set_cache_headers
 
@@ -45,10 +44,6 @@ class FiltersController < ApplicationController
 
   private
 
-  def set_pack
-    use_pack 'settings'
-  end
-
   def set_filter
     @filter = current_account.custom_filters.find(params[:id])
   end
diff --git a/app/controllers/invites_controller.rb b/app/controllers/invites_controller.rb
index 2db4bc5cbd..9bc5164d59 100644
--- a/app/controllers/invites_controller.rb
+++ b/app/controllers/invites_controller.rb
@@ -6,7 +6,6 @@ class InvitesController < ApplicationController
   layout 'admin'
 
   before_action :authenticate_user!
-  before_action :set_pack
   before_action :set_body_classes
   before_action :set_cache_headers
 
@@ -40,10 +39,6 @@ class InvitesController < ApplicationController
 
   private
 
-  def set_pack
-    use_pack 'settings'
-  end
-
   def invites
     current_user.invites.order(id: :desc)
   end
diff --git a/app/controllers/media_controller.rb b/app/controllers/media_controller.rb
index 4c028dbef0..53eee40012 100644
--- a/app/controllers/media_controller.rb
+++ b/app/controllers/media_controller.rb
@@ -10,7 +10,6 @@ class MediaController < ApplicationController
   before_action :verify_permitted_status!
   before_action :check_playable, only: :player
   before_action :allow_iframing, only: :player
-  before_action :set_pack, only: :player
 
   content_security_policy only: :player do |policy|
     policy.frame_ancestors(false)
@@ -48,8 +47,4 @@ class MediaController < ApplicationController
   def allow_iframing
     response.headers.delete('X-Frame-Options')
   end
-
-  def set_pack
-    use_pack 'public'
-  end
 end
diff --git a/app/controllers/oauth/authorizations_controller.rb b/app/controllers/oauth/authorizations_controller.rb
index 62fc9c1b0d..66e774425d 100644
--- a/app/controllers/oauth/authorizations_controller.rb
+++ b/app/controllers/oauth/authorizations_controller.rb
@@ -5,7 +5,6 @@ class Oauth::AuthorizationsController < Doorkeeper::AuthorizationsController
 
   before_action :store_current_location
   before_action :authenticate_resource_owner!
-  before_action :set_pack
   before_action :set_cache_headers
 
   content_security_policy do |p|
@@ -20,10 +19,6 @@ class Oauth::AuthorizationsController < Doorkeeper::AuthorizationsController
     store_location_for(:user, request.url)
   end
 
-  def set_pack
-    use_pack 'auth'
-  end
-
   def render_success
     if skip_authorization? || (matching_token? && !truthy_param?('force_login'))
       redirect_or_render authorize_response
diff --git a/app/controllers/oauth/authorized_applications_controller.rb b/app/controllers/oauth/authorized_applications_controller.rb
index 778912c948..8440df6b7e 100644
--- a/app/controllers/oauth/authorized_applications_controller.rb
+++ b/app/controllers/oauth/authorized_applications_controller.rb
@@ -5,7 +5,6 @@ class Oauth::AuthorizedApplicationsController < Doorkeeper::AuthorizedApplicatio
 
   before_action :store_current_location
   before_action :authenticate_resource_owner!
-  before_action :set_pack
   before_action :require_not_suspended!, only: :destroy
   before_action :set_body_classes
   before_action :set_cache_headers
@@ -31,10 +30,6 @@ class Oauth::AuthorizedApplicationsController < Doorkeeper::AuthorizedApplicatio
     store_location_for(:user, request.url)
   end
 
-  def set_pack
-    use_pack 'settings'
-  end
-
   def require_not_suspended!
     forbidden if current_account.unavailable?
   end
diff --git a/app/controllers/redirect/base_controller.rb b/app/controllers/redirect/base_controller.rb
index ce55cfc53a..90894ec1ed 100644
--- a/app/controllers/redirect/base_controller.rb
+++ b/app/controllers/redirect/base_controller.rb
@@ -3,7 +3,6 @@
 class Redirect::BaseController < ApplicationController
   vary_by 'Accept-Language'
 
-  before_action :set_pack
   before_action :set_resource
   before_action :set_app_body_class
 
@@ -22,8 +21,4 @@ class Redirect::BaseController < ApplicationController
   def set_resource
     raise NotImplementedError
   end
-
-  def set_pack
-    use_pack 'public'
-  end
 end
diff --git a/app/controllers/relationships_controller.rb b/app/controllers/relationships_controller.rb
index e6e7c24752..dd794f3199 100644
--- a/app/controllers/relationships_controller.rb
+++ b/app/controllers/relationships_controller.rb
@@ -5,7 +5,6 @@ class RelationshipsController < ApplicationController
 
   before_action :authenticate_user!
   before_action :set_accounts, only: :show
-  before_action :set_pack
   before_action :set_relationships, only: :show
   before_action :set_body_classes
   before_action :set_cache_headers
@@ -73,10 +72,6 @@ class RelationshipsController < ApplicationController
     @body_classes = 'admin'
   end
 
-  def set_pack
-    use_pack 'admin'
-  end
-
   def set_cache_headers
     response.cache_control.replace(private: true, no_store: true)
   end
diff --git a/app/controllers/settings/base_controller.rb b/app/controllers/settings/base_controller.rb
index 4d3d6e6a1b..f15140aa2b 100644
--- a/app/controllers/settings/base_controller.rb
+++ b/app/controllers/settings/base_controller.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 class Settings::BaseController < ApplicationController
-  before_action :set_pack
   layout 'admin'
 
   before_action :authenticate_user!
@@ -10,10 +9,6 @@ class Settings::BaseController < ApplicationController
 
   private
 
-  def set_pack
-    use_pack 'settings'
-  end
-
   def set_body_classes
     @body_classes = 'admin'
   end
diff --git a/app/controllers/settings/login_activities_controller.rb b/app/controllers/settings/login_activities_controller.rb
index 018fc7e950..50e2d70cb9 100644
--- a/app/controllers/settings/login_activities_controller.rb
+++ b/app/controllers/settings/login_activities_controller.rb
@@ -7,10 +7,4 @@ class Settings::LoginActivitiesController < Settings::BaseController
   def index
     @login_activities = LoginActivity.where(user: current_user).order(id: :desc).page(params[:page])
   end
-
-  private
-
-  def set_pack
-    use_pack 'settings'
-  end
 end
diff --git a/app/controllers/settings/two_factor_authentication/webauthn_credentials_controller.rb b/app/controllers/settings/two_factor_authentication/webauthn_credentials_controller.rb
index aed5af6e79..9714d54f95 100644
--- a/app/controllers/settings/two_factor_authentication/webauthn_credentials_controller.rb
+++ b/app/controllers/settings/two_factor_authentication/webauthn_credentials_controller.rb
@@ -85,10 +85,6 @@ module Settings
 
       private
 
-      def set_pack
-        use_pack 'auth'
-      end
-
       def redirect_invalid_otp
         flash[:error] = t('webauthn_credentials.otp_required')
         redirect_to settings_two_factor_authentication_methods_path
diff --git a/app/controllers/shares_controller.rb b/app/controllers/shares_controller.rb
index e13e7e8b65..6546b84978 100644
--- a/app/controllers/shares_controller.rb
+++ b/app/controllers/shares_controller.rb
@@ -4,17 +4,12 @@ class SharesController < ApplicationController
   layout 'modal'
 
   before_action :authenticate_user!
-  before_action :set_pack
   before_action :set_body_classes
 
   def show; end
 
   private
 
-  def set_pack
-    use_pack 'share'
-  end
-
   def set_body_classes
     @body_classes = 'modal-layout compose-standalone'
   end
diff --git a/app/controllers/statuses_cleanup_controller.rb b/app/controllers/statuses_cleanup_controller.rb
index 88cf26d74d..4a3fc10ca4 100644
--- a/app/controllers/statuses_cleanup_controller.rb
+++ b/app/controllers/statuses_cleanup_controller.rb
@@ -6,7 +6,6 @@ class StatusesCleanupController < ApplicationController
   before_action :authenticate_user!
   before_action :set_policy
   before_action :set_body_classes
-  before_action :set_pack
   before_action :set_cache_headers
 
   def show; end
@@ -27,10 +26,6 @@ class StatusesCleanupController < ApplicationController
 
   private
 
-  def set_pack
-    use_pack 'settings'
-  end
-
   def set_policy
     @policy = current_account.statuses_cleanup_policy || current_account.build_statuses_cleanup_policy(enabled: false)
   end
diff --git a/app/controllers/statuses_controller.rb b/app/controllers/statuses_controller.rb
index 7f9127d3a6..db7eddd78b 100644
--- a/app/controllers/statuses_controller.rb
+++ b/app/controllers/statuses_controller.rb
@@ -41,7 +41,6 @@ class StatusesController < ApplicationController
   end
 
   def embed
-    use_pack 'public'
     return not_found if @status.hidden? || @status.reblog?
 
     expires_in 180, public: true
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 233c242e4a..62c0e78d23 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -233,6 +233,21 @@ module ApplicationHelper
     EmojiFormatter.new(html, custom_emojis, other_options.merge(animate: prefers_autoplay?)).to_s
   end
 
+  # glitch-soc addition to handle the multiple flavors
+  def preload_locale_pack
+    supported_locales = Themes.instance.flavour(current_flavour)['locales']
+    preload_pack_asset "locales/#{current_flavour}/#{I18n.locale}-json.js" if supported_locales.include?(I18n.locale.to_s)
+  end
+
+  def flavoured_javascript_pack_tag(pack_name, **options)
+    javascript_pack_tag("flavours/#{current_flavour}/#{pack_name}", **options)
+  end
+
+  def preload_signed_in_js_packs
+    preload_files = Themes.instance.flavour(current_flavour)&.fetch('signed_in_preload', nil) || []
+    safe_join(preload_files.map { |entry| preload_pack_asset entry })
+  end
+
   private
 
   def storage_host_var
diff --git a/app/javascript/flavours/glitch/theme.yml b/app/javascript/flavours/glitch/theme.yml
index 99a31cb663..ca18fd7b86 100644
--- a/app/javascript/flavours/glitch/theme.yml
+++ b/app/javascript/flavours/glitch/theme.yml
@@ -1,32 +1,12 @@
-#  (REQUIRED) The location of the pack files.
-pack:
-  admin:
-    - admin.tsx
-    - public.tsx
-  auth:
-    - public.tsx
-    - two_factor_authentication.js
-  common:
-    filename: common.js
-    stylesheet: true
-  error: error.js
-  application:
-    filename: application.js
-    preload:
-      - flavours/glitch/async/compose
-      - flavours/glitch/async/home_timeline
-      - flavours/glitch/async/notifications
-  inert:
-    filename: inert.js
-    stylesheet: true
-  mailer:
-    filename: mailer.js
-    stylesheet: true
-  public: public.tsx
-  settings: public.tsx
-  sign_up: sign_up.js
-  share: share.jsx
-  remote_interaction_helper: remote_interaction_helper.ts
+#  (REQUIRED) The directory which contains the entry point files.
+pack_directory: app/javascript/flavours/glitch/packs
+
+#  (OPTIONAL) Define files to be preloaded when a logged-in user is
+#  visiting the main web app.
+signed_in_preload:
+  - flavours/glitch/async/compose.js
+  - flavours/glitch/async/home_timeline.js
+  - flavours/glitch/async/notifications.js
 
 #  (OPTIONAL) The directory which contains localization files for
 #  the flavour, relative to this directory. The contents of this
@@ -40,14 +20,3 @@ inherit_locales: vanilla
 #  (OPTIONAL) A file to use as the preview screenshot for the flavour,
 #  or an array thereof. These are the full path from `app/javascript/`.
 screenshot: flavours/glitch/images/glitch-preview.png
-
-#  (OPTIONAL) The directory which contains the pack files.
-#  Defaults to this directory (`app/javascript/flavour/[flavour]`),
-#  but in the case of the vanilla Mastodon flavour the pack files are
-#  somewhere else.
-pack_directory: app/javascript/flavours/glitch/packs
-#  (OPTIONAL) The directory which contains the pack files.
-#  Defaults to the theme directory (`app/javascript/themes/[theme]`),
-#  which should be sufficient for like 99% of use-cases lol.
-
-#      pack_directory: app/javascript/packs
diff --git a/app/javascript/flavours/vanilla/theme.yml b/app/javascript/flavours/vanilla/theme.yml
index 61ee528f96..d155324beb 100644
--- a/app/javascript/flavours/vanilla/theme.yml
+++ b/app/javascript/flavours/vanilla/theme.yml
@@ -1,32 +1,12 @@
-#  (REQUIRED) The location of the pack files inside `pack_directory`.
-pack:
-  admin:
-    - admin.tsx
-    - public.tsx
-  auth:
-    - public.tsx
-    - two_factor_authentication.js
-  common:
-    filename: common.js
-    stylesheet: true
-  error: error.js
-  application:
-    filename: application.js
-    preload:
-      - features/compose
-      - features/home_timeline
-      - features/notifications
-  inert:
-    filename: inert.js
-    stylesheet: true
-  mailer:
-    filename: mailer.js
-    stylesheet: true
-  public: public.tsx
-  settings: public.tsx
-  sign_up: sign_up.js
-  share: share.jsx
-  remote_interaction_helper: remote_interaction_helper.ts
+#  (REQUIRED) The directory which contains the pack files.
+pack_directory: app/javascript/packs
+
+#  (OPTIONAL) Define files to be preloaded when a logged-in user is
+#  visiting the main web app.
+signed_in_preload:
+  - features/compose.js
+  - features/home_timeline.js
+  - features/notifications.js
 
 #  (OPTIONAL) The directory which contains localization files for
 #  the flavour, relative to this directory.
@@ -35,9 +15,3 @@ locales: ../../mastodon/locales
 #  (OPTIONAL) A file to use as the preview screenshot for the flavour,
 #  or an array thereof. These are the full path from `app/javascript/`.
 screenshot: images/screenshot.png
-
-#  (OPTIONAL) The directory which contains the pack files.
-#  Defaults to this directory (`app/javascript/flavour/[flavour]`),
-#  but in the case of the vanilla Mastodon flavour the pack files are
-#  somewhere else.
-pack_directory: app/javascript/packs
diff --git a/app/lib/themes.rb b/app/lib/themes.rb
index b379e139e9..89730c9b31 100644
--- a/app/lib/themes.rb
+++ b/app/lib/themes.rb
@@ -11,7 +11,7 @@ class Themes
 
     Rails.root.glob('app/javascript/flavours/*/theme.yml') do |pathname|
       data = YAML.load_file(pathname)
-      next unless data['pack']
+      next unless data['pack_directory']
 
       dir = pathname.dirname
       name = dir.basename.to_s
diff --git a/app/views/auth/sessions/two_factor.html.haml b/app/views/auth/sessions/two_factor.html.haml
index 0892101b57..63c8b0a2cb 100644
--- a/app/views/auth/sessions/two_factor.html.haml
+++ b/app/views/auth/sessions/two_factor.html.haml
@@ -1,6 +1,8 @@
 - content_for :page_title do
   = t('auth.login')
 
+= flavoured_javascript_pack_tag 'two_factor_authentication', crossorigin: 'anonymous'
+
 - if webauthn_enabled?
   = render partial: 'auth/sessions/two_factor/webauthn_form', locals: { hidden: @scheme_type != 'webauthn' }
 
diff --git a/app/views/auth/setup/show.html.haml b/app/views/auth/setup/show.html.haml
index 097e3416e2..6ba219e729 100644
--- a/app/views/auth/setup/show.html.haml
+++ b/app/views/auth/setup/show.html.haml
@@ -1,6 +1,8 @@
 - content_for :page_title do
   = t('auth.setup.title')
 
+= flavoured_javascript_pack_tag 'sign_up', crossorigin: 'anonymous'
+
 = simple_form_for(@user, url: auth_setup_path) do |f|
   = render 'auth/shared/progress', stage: 'confirm'
 
diff --git a/app/views/layouts/_theme.html.haml b/app/views/layouts/_theme.html.haml
deleted file mode 100644
index fd493bf899..0000000000
--- a/app/views/layouts/_theme.html.haml
+++ /dev/null
@@ -1,5 +0,0 @@
-- if theme && theme[:pack]
-  - pack_path = "flavours/#{theme[:flavour]}/#{theme[:pack]}"
-  = javascript_pack_tag pack_path, crossorigin: 'anonymous'
-  - theme[:preload]&.each do |link|
-    %link{ href: asset_pack_path("#{link}.js"), crossorigin: 'anonymous', rel: 'preload', as: 'script' }/
diff --git a/app/views/layouts/admin.html.haml b/app/views/layouts/admin.html.haml
index 3048e0e6ad..a95d5caef5 100644
--- a/app/views/layouts/admin.html.haml
+++ b/app/views/layouts/admin.html.haml
@@ -1,5 +1,7 @@
 - content_for :header_tags do
   = render_initial_state
+  = flavoured_javascript_pack_tag 'public', crossorigin: 'anonymous'
+  = flavoured_javascript_pack_tag 'admin', async: true, crossorigin: 'anonymous'
 
 - content_for :content do
   .admin-wrapper
diff --git a/app/views/layouts/application.html.haml b/app/views/layouts/application.html.haml
index 8734f7e7d4..4fe314eb4b 100755
--- a/app/views/layouts/application.html.haml
+++ b/app/views/layouts/application.html.haml
@@ -33,11 +33,7 @@
     = stylesheet_pack_tag 'flavours/vanilla/inert', media: 'all', id: 'inert-style'
 
     = javascript_pack_tag 'common', crossorigin: 'anonymous'
-    - if @theme
-      - if @theme[:supported_locales].include? I18n.locale.to_s
-        = preload_pack_asset "locales/#{@theme[:flavour]}/#{I18n.locale}-json.js"
-      - elsif @theme[:supported_locales].include? 'en'
-        = preload_pack_asset "locales/#{@theme[:flavour]}/en-json.js"
+    = preload_locale_pack
     = csrf_meta_tags unless skip_csrf_meta_tags?
     %meta{ name: 'style-nonce', content: request.content_security_policy_nonce }
 
@@ -45,9 +41,6 @@
 
     = yield :header_tags
 
-    -# These must come after :header_tags to ensure our initial state has been defined.
-    = render partial: 'layouts/theme', object: @theme
-
   %body{ class: body_classes }
     = content_for?(:content) ? yield(:content) : yield
 
diff --git a/app/views/layouts/auth.html.haml b/app/views/layouts/auth.html.haml
index 34f6b38ec8..efd2569d77 100644
--- a/app/views/layouts/auth.html.haml
+++ b/app/views/layouts/auth.html.haml
@@ -1,3 +1,6 @@
+- content_for :header_tags do
+  = flavoured_javascript_pack_tag 'public', crossorigin: 'anonymous'
+
 - content_for :content do
   .container-alt
     .logo-container
diff --git a/app/views/layouts/embedded.html.haml b/app/views/layouts/embedded.html.haml
index 19df497533..e8764567d1 100644
--- a/app/views/layouts/embedded.html.haml
+++ b/app/views/layouts/embedded.html.haml
@@ -14,14 +14,9 @@
     = stylesheet_pack_tag 'flavours/vanilla/common', media: 'all', crossorigin: 'anonymous' # upstream uses `common` but that's implicitly defined
     = stylesheet_pack_tag current_theme, media: 'all', crossorigin: 'anonymous'
     = javascript_pack_tag 'common', integrity: true, crossorigin: 'anonymous'
-    - if @theme
-      - if @theme[:supported_locales].include? I18n.locale.to_s
-        = preload_pack_asset "locales/#{@theme[:flavour]}/#{I18n.locale}-json.js"
-      - elsif @theme[:supported_locales].include? 'en'
-        = preload_pack_asset "locales/#{@theme[:flavour]}/en-json.js"
-    = preload_pack_asset "locale/#{I18n.locale}-json.js"
+    = preload_locale_pack
     = render_initial_state
-    = render partial: 'layouts/theme', object: @theme
+    = flavoured_javascript_pack_tag 'public', integrity: true, crossorigin: 'anonymous'
 
   %body.embed
     = yield
diff --git a/app/views/layouts/error.html.haml b/app/views/layouts/error.html.haml
index 49224daa83..7ad2ad3d69 100644
--- a/app/views/layouts/error.html.haml
+++ b/app/views/layouts/error.html.haml
@@ -8,7 +8,7 @@
     = stylesheet_pack_tag 'flavours/vanilla/common', media: 'all', crossorigin: 'anonymous' # upstream uses `common` but that's implicitly defined
     = stylesheet_pack_tag current_theme, media: 'all', crossorigin: 'anonymous'
     = javascript_pack_tag 'common', crossorigin: 'anonymous'
-    = render partial: 'layouts/theme', object: @theme || { pack: 'error', flavour: 'glitch', common: { pack: 'common', flavour: 'glitch', skin: 'default' } }
+    = flavoured_javascript_pack_tag 'error', crossorigin: 'anonymous'
   %body.error
     .dialog
       .dialog__illustration
diff --git a/app/views/layouts/modal.html.haml b/app/views/layouts/modal.html.haml
index 5d08d78489..8d5b158eb5 100644
--- a/app/views/layouts/modal.html.haml
+++ b/app/views/layouts/modal.html.haml
@@ -1,3 +1,6 @@
+- content_for :header_tags do
+  = flavoured_javascript_pack_tag 'public', crossorigin: 'anonymous'
+
 - content_for :content do
   - if user_signed_in? && !@hide_header
     .account-header
diff --git a/app/views/media/player.html.haml b/app/views/media/player.html.haml
index 9a0c420fc3..c5ba8680a0 100644
--- a/app/views/media/player.html.haml
+++ b/app/views/media/player.html.haml
@@ -1,12 +1,6 @@
 - content_for :header_tags do
   = render_initial_state
-  = javascript_pack_tag 'common', crossorigin: 'anonymous'
-  - if @theme
-    - if @theme[:supported_locales].include? I18n.locale.to_s
-      = preload_pack_asset "locales/#{@theme[:flavour]}/#{I18n.locale}-json.js"
-    - elsif @theme[:supported_locales].include? 'en'
-      = preload_pack_asset "locales/#{@theme[:flavour]}/en-json.js"
-  = render partial: 'layouts/theme', object: @theme
+  = flavoured_javascript_pack_tag 'public', crossorigin: 'anonymous'
 
 :ruby
   meta = @media_attachment.file.meta || {}
diff --git a/app/views/relationships/show.html.haml b/app/views/relationships/show.html.haml
index 6b87bef2ec..066f5d17fb 100644
--- a/app/views/relationships/show.html.haml
+++ b/app/views/relationships/show.html.haml
@@ -1,6 +1,9 @@
 - content_for :page_title do
   = t('settings.relationships')
 
+- content_for :header_tags do
+  = flavoured_javascript_pack_tag 'admin', async: true, crossorigin: 'anonymous'
+
 .filters
   .filter-subset
     %strong= t 'relationships.relationship'
diff --git a/app/views/remote_interaction_helper/index.html.haml b/app/views/remote_interaction_helper/index.html.haml
index 84a48bf057..e67fe6b6b7 100644
--- a/app/views/remote_interaction_helper/index.html.haml
+++ b/app/views/remote_interaction_helper/index.html.haml
@@ -1,4 +1,4 @@
 - content_for :header_tags do
   %meta{ name: 'robots', content: 'noindex' }/
 
-  = javascript_pack_tag 'flavours/vanilla/remote_interaction_helper', crossorigin: 'anonymous'
+  = flavoured_javascript_pack_tag 'remote_interaction_helper', crossorigin: 'anonymous'
diff --git a/app/views/settings/two_factor_authentication/webauthn_credentials/new.html.haml b/app/views/settings/two_factor_authentication/webauthn_credentials/new.html.haml
index 5ec0247577..444cf6ae74 100644
--- a/app/views/settings/two_factor_authentication/webauthn_credentials/new.html.haml
+++ b/app/views/settings/two_factor_authentication/webauthn_credentials/new.html.haml
@@ -12,3 +12,5 @@
 
   .actions
     = f.button :button, t('webauthn_credentials.add'), class: 'js-webauthn', type: :submit
+
+= flavoured_javascript_pack_tag 'two_factor_authentication', crossorigin: 'anonymous'
diff --git a/app/views/shared/_web_app.html.haml b/app/views/shared/_web_app.html.haml
index b53c25e77c..cb9f7f4cfd 100644
--- a/app/views/shared/_web_app.html.haml
+++ b/app/views/shared/_web_app.html.haml
@@ -1,10 +1,12 @@
 - content_for :header_tags do
   - if user_signed_in?
+    = preload_signed_in_js_packs
     %meta{ name: 'initialPath', content: request.path }
 
   %meta{ name: 'applicationServerKey', content: Rails.configuration.x.vapid_public_key }
 
   = render_initial_state
+  = flavoured_javascript_pack_tag 'application', crossorigin: 'anonymous'
 
 .notranslate.app-holder#mastodon{ data: { props: Oj.dump(default_props) } }
   %noscript
diff --git a/app/views/shares/show.html.haml b/app/views/shares/show.html.haml
index 28910d3abd..350604527d 100644
--- a/app/views/shares/show.html.haml
+++ b/app/views/shares/show.html.haml
@@ -1,4 +1,5 @@
 - content_for :header_tags do
   = render_initial_state
+  = flavoured_javascript_pack_tag 'share', crossorigin: 'anonymous'
 
 #mastodon-compose{ data: { props: Oj.dump(default_props) } }
diff --git a/config/webpack/configuration.js b/config/webpack/configuration.js
index 7ec28158e7..c9a1fe268a 100644
--- a/config/webpack/configuration.js
+++ b/config/webpack/configuration.js
@@ -14,18 +14,15 @@ const skinFiles = glob.sync('app/javascript/skins/*/*');
 const flavours = {};
 
 flavourFiles.forEach((flavourFile) => {
-  const data = load(readFileSync(flavourFile), 'utf8');
-  data.name = basename(dirname(flavourFile));
-  data.skin = {};
-  if (!data.pack_directory) {
-    data.pack_directory = dirname(flavourFile);
-  }
-  if (data.locales) {
-    data.locales = join(dirname(flavourFile), data.locales);
-  }
-  if (data.pack && typeof data.pack === 'object') {
-    flavours[data.name] = data;
-  }
+  const { locales, inherit_locales, pack_directory } = load(readFileSync(flavourFile), 'utf8');
+
+  flavours[basename(dirname(flavourFile))] = {
+    name: basename(dirname(flavourFile)),
+    locales: locales ? join(dirname(flavourFile), locales) : null,
+    inherit_locales,
+    pack_directory: pack_directory,
+    skin: {},
+  };
 });
 
 skinFiles.forEach((skinFile) => {
diff --git a/config/webpack/shared.js b/config/webpack/shared.js
index 404dc23d6e..df61dff312 100644
--- a/config/webpack/shared.js
+++ b/config/webpack/shared.js
@@ -1,36 +1,26 @@
 // Note: You must restart bin/webpack-dev-server for changes to take effect
 
-const { resolve } = require('path');
+const { basename, dirname, join, relative, resolve } = require('path');
 
 const CircularDependencyPlugin = require('circular-dependency-plugin');
+const { sync } = require('glob');
 const MiniCssExtractPlugin = require('mini-css-extract-plugin');
+const extname = require('path-complete-extname');
 const webpack = require('webpack');
 const AssetsManifestPlugin = require('webpack-assets-manifest');
 
 const { env, settings, flavours, output } = require('./configuration');
 const rules = require('./rules');
 
-function reducePacks (data, into = {}) {
-  if (!data.pack) return into;
+const extensionGlob = `**/*{${settings.extensions.join(',')}}*`;
 
-  for (const entry in data.pack) {
-    const pack = data.pack[entry];
-    if (!pack) continue;
+function reduceFlavourPacks(data, into = {}) {
+  const packPaths = sync(join(data.pack_directory, extensionGlob));
 
-    let packFiles = [];
-    if (typeof pack === 'string')
-      packFiles = [pack];
-    else if (Array.isArray(pack))
-      packFiles = pack;
-    else
-      packFiles = [pack.filename];
-
-    if (packFiles) {
-      into[`flavours/${data.name}/${entry}`] = packFiles.map(packFile => resolve(data.pack_directory, packFile));
-    }
-  }
-
-  if (!data.name) return into;
+  packPaths.forEach((entry) => {
+    const namespace = relative(join(data.pack_directory), dirname(entry));
+    into[`flavours/${data.name}/${join(namespace, basename(entry, extname(entry)))}`] = resolve(entry);
+  });
 
   for (const skinName in data.skin) {
     const skin = data.skin[skinName];
@@ -43,7 +33,7 @@ function reducePacks (data, into = {}) {
 }
 
 const entries = Object.assign(
-  Object.values(flavours).reduce((map, data) => reducePacks(data, map), {}),
+  Object.values(flavours).reduce((map, data) => reduceFlavourPacks(data, map), {}),
 );
 
 
diff --git a/spec/views/statuses/show.html.haml_spec.rb b/spec/views/statuses/show.html.haml_spec.rb
index 92ba678b6d..779fe6e5f4 100644
--- a/spec/views/statuses/show.html.haml_spec.rb
+++ b/spec/views/statuses/show.html.haml_spec.rb
@@ -4,7 +4,7 @@ require 'rails_helper'
 
 describe 'statuses/show.html.haml', :without_verify_partial_doubles do
   before do
-    allow(view).to receive_messages(api_oembed_url: '', site_title: 'example site', site_hostname: 'example.com', full_asset_url: '//asset.host/image.svg', current_account: nil, single_user_mode?: false)
+    allow(view).to receive_messages(api_oembed_url: '', site_title: 'example site', site_hostname: 'example.com', full_asset_url: '//asset.host/image.svg', current_flavour: 'glitch', current_account: nil, single_user_mode?: false)
     allow(view).to receive(:local_time)
     allow(view).to receive(:local_time_ago)
     assign(:instance_presenter, InstancePresenter.new)