diff --git a/app/assets/javascripts/admin/addon/mixins/setting-component.js b/app/assets/javascripts/admin/addon/mixins/setting-component.js
index 8ffcd1d8489..4af6d3a357c 100644
--- a/app/assets/javascripts/admin/addon/mixins/setting-component.js
+++ b/app/assets/javascripts/admin/addon/mixins/setting-component.js
@@ -9,7 +9,10 @@ import { Promise } from "rsvp";
 import JsonSchemaEditorModal from "discourse/components/modal/json-schema-editor";
 import { ajax } from "discourse/lib/ajax";
 import { fmt, propertyNotEqual } from "discourse/lib/computed";
-import { SITE_SETTING_REQUIRES_CONFIRMATION_TYPES } from "discourse/lib/constants";
+import {
+  DEFAULT_USER_PREFERENCES,
+  SITE_SETTING_REQUIRES_CONFIRMATION_TYPES,
+} from "discourse/lib/constants";
 import { deepEqual } from "discourse/lib/object";
 import { humanizedSettingName } from "discourse/lib/site-settings-utils";
 import { splitString } from "discourse/lib/utilities";
@@ -44,45 +47,6 @@ const CUSTOM_TYPES = [
 
 const AUTO_REFRESH_ON_SAVE = ["logo", "logo_small", "large_icon"];
 
-const DEFAULT_USER_PREFERENCES = [
-  "default_email_digest_frequency",
-  "default_include_tl0_in_digests",
-  "default_email_level",
-  "default_email_messages_level",
-  "default_email_mailing_list_mode",
-  "default_email_mailing_list_mode_frequency",
-  "default_email_previous_replies",
-  "default_email_in_reply_to",
-  "default_hide_profile",
-  "default_hide_presence",
-  "default_other_new_topic_duration_minutes",
-  "default_other_auto_track_topics_after_msecs",
-  "default_other_notification_level_when_replying",
-  "default_other_external_links_in_new_tab",
-  "default_other_enable_quoting",
-  "default_other_enable_smart_lists",
-  "default_other_enable_defer",
-  "default_other_dynamic_favicon",
-  "default_other_like_notification_frequency",
-  "default_other_skip_new_user_tips",
-  "default_topics_automatic_unpin",
-  "default_categories_watching",
-  "default_categories_tracking",
-  "default_categories_muted",
-  "default_categories_watching_first_post",
-  "default_categories_normal",
-  "default_tags_watching",
-  "default_tags_tracking",
-  "default_tags_muted",
-  "default_tags_watching_first_post",
-  "default_text_size",
-  "default_title_count_mode",
-  "default_navigation_menu_categories",
-  "default_navigation_menu_tags",
-  "default_sidebar_link_to_filtered_list",
-  "default_sidebar_show_count_of_new_items",
-];
-
 export default Mixin.create({
   modal: service(),
   router: service(),
diff --git a/app/assets/javascripts/discourse/app/lib/constants.js b/app/assets/javascripts/discourse/app/lib/constants.js
index f2fadc2863a..8583697ea2a 100644
--- a/app/assets/javascripts/discourse/app/lib/constants.js
+++ b/app/assets/javascripts/discourse/app/lib/constants.js
@@ -102,6 +102,45 @@ export const SITE_SETTING_REQUIRES_CONFIRMATION_TYPES = {
   user_option: "user_option",
 };
 
+export const DEFAULT_USER_PREFERENCES = [
+  "default_email_digest_frequency",
+  "default_include_tl0_in_digests",
+  "default_email_level",
+  "default_email_messages_level",
+  "default_email_mailing_list_mode",
+  "default_email_mailing_list_mode_frequency",
+  "default_email_previous_replies",
+  "default_email_in_reply_to",
+  "default_hide_profile",
+  "default_hide_presence",
+  "default_other_new_topic_duration_minutes",
+  "default_other_auto_track_topics_after_msecs",
+  "default_other_notification_level_when_replying",
+  "default_other_external_links_in_new_tab",
+  "default_other_enable_quoting",
+  "default_other_enable_smart_lists",
+  "default_other_enable_defer",
+  "default_other_dynamic_favicon",
+  "default_other_like_notification_frequency",
+  "default_other_skip_new_user_tips",
+  "default_topics_automatic_unpin",
+  "default_categories_watching",
+  "default_categories_tracking",
+  "default_categories_muted",
+  "default_categories_watching_first_post",
+  "default_categories_normal",
+  "default_tags_watching",
+  "default_tags_tracking",
+  "default_tags_muted",
+  "default_tags_watching_first_post",
+  "default_text_size",
+  "default_title_count_mode",
+  "default_navigation_menu_categories",
+  "default_navigation_menu_tags",
+  "default_sidebar_link_to_filtered_list",
+  "default_sidebar_show_count_of_new_items",
+];
+
 export const MAX_UNOPTIMIZED_CATEGORIES = 1000;
 
 export const USER_FIELD_FLAGS = [
diff --git a/app/controllers/admin/config/about_controller.rb b/app/controllers/admin/config/about_controller.rb
index ccb6ff2f99f..e760333f0b7 100644
--- a/app/controllers/admin/config/about_controller.rb
+++ b/app/controllers/admin/config/about_controller.rb
@@ -5,41 +5,62 @@ class Admin::Config::AboutController < Admin::AdminController
   end
 
   def update
-    settings_map = {}
-    if general_settings = params[:general_settings]
-      settings_map[:title] = general_settings[:name]
-      settings_map[:site_description] = general_settings[:summary]
-      settings_map[:about_banner_image] = general_settings[:about_banner_image]
+    settings = []
 
-      settings_map[:extended_site_description] = general_settings[:extended_description]
-      settings_map[:short_site_description] = general_settings[:community_title]
-      if settings_map[:extended_site_description].present?
-        settings_map[:extended_site_description_cooked] = PrettyText.markdown(
-          settings_map[:extended_site_description],
-        )
+    if general_settings = params[:general_settings]
+      settings << { setting_name: "title", value: general_settings[:name] }
+      settings << { setting_name: "site_description", value: general_settings[:summary] }
+      settings << {
+        setting_name: "about_banner_image",
+        value: general_settings[:about_banner_image],
+      }
+
+      settings << {
+        setting_name: "extended_site_description",
+        value: general_settings[:extended_description],
+      }
+      settings << {
+        setting_name: "short_site_description",
+        value: general_settings[:community_title],
+      }
+
+      if general_settings[:extended_description].present?
+        settings << {
+          setting_name: "extended_site_description_cooked",
+          value: PrettyText.markdown(general_settings[:extended_description]),
+        }
       else
-        settings_map[:extended_site_description_cooked] = ""
+        settings << { setting_name: "extended_site_description_cooked", value: "" }
       end
     end
 
     if contact_information = params[:contact_information]
-      settings_map[:community_owner] = contact_information[:community_owner]
-      settings_map[:contact_email] = contact_information[:contact_email]
-      settings_map[:contact_url] = contact_information[:contact_url]
-      settings_map[:site_contact_username] = contact_information[:contact_username]
-      settings_map[:site_contact_group_name] = contact_information[:contact_group_name]
+      settings << { setting_name: "community_owner", value: contact_information[:community_owner] }
+      settings << { setting_name: "contact_email", value: contact_information[:contact_email] }
+      settings << { setting_name: "contact_url", value: contact_information[:contact_url] }
+      settings << {
+        setting_name: "site_contact_username",
+        value: contact_information[:contact_username],
+      }
+      settings << {
+        setting_name: "site_contact_group_name",
+        value: contact_information[:contact_group_name],
+      }
     end
 
     if your_organization = params[:your_organization]
-      settings_map[:company_name] = your_organization[:company_name]
-      settings_map[:governing_law] = your_organization[:governing_law]
-      settings_map[:city_for_disputes] = your_organization[:city_for_disputes]
+      settings << { setting_name: "company_name", value: your_organization[:company_name] }
+      settings << { setting_name: "governing_law", value: your_organization[:governing_law] }
+      settings << {
+        setting_name: "city_for_disputes",
+        value: your_organization[:city_for_disputes],
+      }
     end
 
     SiteSetting::Update.call(
       guardian:,
       params: {
-        settings: settings_map,
+        settings:,
       },
       options: {
         allow_changing_hidden: %i[
diff --git a/app/controllers/admin/config/branding_controller.rb b/app/controllers/admin/config/branding_controller.rb
index 4602d65b9a8..fc39d2ff070 100644
--- a/app/controllers/admin/config/branding_controller.rb
+++ b/app/controllers/admin/config/branding_controller.rb
@@ -4,27 +4,25 @@ class Admin::Config::BrandingController < Admin::AdminController
   end
 
   def logo
-    SiteSetting::Update.call(
-      guardian:,
-      params: {
-        settings: {
-          logo: params[:logo],
-          logo_dark: params[:logo_dark],
-          large_icon: params[:large_icon],
-          favicon: params[:favicon],
-          logo_small: params[:logo_small],
-          logo_small_dark: params[:logo_small_dark],
-          mobile_logo: params[:mobile_logo],
-          mobile_logo_dark: params[:mobile_logo_dark],
-          manifest_icon: params[:manifest_icon],
-          manifest_screenshots: params[:manifest_screenshots],
-          apple_touch_icon: params[:apple_touch_icon],
-          digest_logo: params[:digest_logo],
-          opengraph_image: params[:opengraph_image],
-          x_summary_large_image: params[:x_summary_large_image],
-        },
-      },
-    ) do
+    settings =
+      %i[
+        logo
+        logo_dark
+        large_icon
+        favicon
+        logo_small
+        logo_small_dark
+        mobile_logo
+        mobile_logo_dark
+        manifest_icon
+        manifest_screenshots
+        apple_touch_icon
+        digest_logo
+        opengraph_image
+        x_summary_large_image
+      ].map { |setting| { setting_name: setting, value: params[setting] } }
+
+    SiteSetting::Update.call(guardian:, params: { settings: }) do
       on_success { render json: success_json }
       on_failed_policy(:settings_are_visible) do |policy|
         raise Discourse::InvalidParameters, policy.reason
diff --git a/app/controllers/admin/site_settings_controller.rb b/app/controllers/admin/site_settings_controller.rb
index 1b109db4f20..b4cb36e982e 100644
--- a/app/controllers/admin/site_settings_controller.rb
+++ b/app/controllers/admin/site_settings_controller.rb
@@ -20,19 +20,12 @@ class Admin::SiteSettingsController < Admin::AdminController
   def update
     params.require(:id)
     id = params[:id]
-    update_existing_users = params[:update_existing_user].present?
+    backfill = params[:update_existing_user]
 
-    previous_value = value_or_default(SiteSetting.get(id)) if update_existing_users
+    settings = [{ setting_name: id, value: params[id], backfill: }]
 
-    SiteSetting::Update.call(params: { settings: { id => params[id] } }, guardian:) do
-      on_success do |params:|
-        if update_existing_users
-          params.settings.to_a.each do |setting_name, setting_value|
-            SiteSettingUpdateExistingUsers.call(setting_name.to_s, setting_value, previous_value)
-          end
-        end
-        render body: nil
-      end
+    SiteSetting::Update.call(params: { settings: }, guardian:) do
+      on_success { render body: nil }
       on_failed_policy(:settings_are_not_deprecated) do |policy|
         raise Discourse::InvalidParameters, policy.reason
       end
diff --git a/app/models/site_setting.rb b/app/models/site_setting.rb
index e5d58cbf59f..82c89c9c88d 100644
--- a/app/models/site_setting.rb
+++ b/app/models/site_setting.rb
@@ -16,6 +16,45 @@ class SiteSetting < ActiveRecord::Base
     trust_levels
   ]
 
+  DEFAULT_USER_PREFERENCES = %w[
+    default_email_digest_frequency
+    default_include_tl0_in_digests
+    default_email_level
+    default_email_messages_level
+    default_email_mailing_list_mode
+    default_email_mailing_list_mode_frequency
+    default_email_previous_replies
+    default_email_in_reply_to
+    default_hide_profile
+    default_hide_presence
+    default_other_new_topic_duration_minutes
+    default_other_auto_track_topics_after_msecs
+    default_other_notification_level_when_replying
+    default_other_external_links_in_new_tab
+    default_other_enable_quoting
+    default_other_enable_smart_lists
+    default_other_enable_defer
+    default_other_dynamic_favicon
+    default_other_like_notification_frequency
+    default_other_skip_new_user_tips
+    default_topics_automatic_unpin
+    default_categories_watching
+    default_categories_tracking
+    default_categories_muted
+    default_categories_watching_first_post
+    default_categories_normal
+    default_tags_watching
+    default_tags_tracking
+    default_tags_muted
+    default_tags_watching_first_post
+    default_text_size
+    default_title_count_mode
+    default_navigation_menu_categories
+    default_navigation_menu_tags
+    default_sidebar_link_to_filtered_list
+    default_sidebar_show_count_of_new_items
+  ]
+
   extend GlobalPath
   extend SiteSettingExtension
 
diff --git a/app/services/site_setting/policy/settings_are_configurable.rb b/app/services/site_setting/policy/settings_are_configurable.rb
index c7e8b5243e9..9749e8e98bf 100644
--- a/app/services/site_setting/policy/settings_are_configurable.rb
+++ b/app/services/site_setting/policy/settings_are_configurable.rb
@@ -4,7 +4,7 @@ class SiteSetting::Policy::SettingsAreConfigurable < Service::PolicyBase
   delegate :options, :params, to: :context
 
   def call
-    @unconfigurable_settings = params.settings.keys.select(&method(:validate_setting))
+    @unconfigurable_settings = params.settings.map(&:name).select(&method(:validate_setting))
     @unconfigurable_settings.empty?
   end
 
diff --git a/app/services/site_setting/policy/settings_are_not_deprecated.rb b/app/services/site_setting/policy/settings_are_not_deprecated.rb
index 1ca43e47b10..3a9f9aadb6d 100644
--- a/app/services/site_setting/policy/settings_are_not_deprecated.rb
+++ b/app/services/site_setting/policy/settings_are_not_deprecated.rb
@@ -5,9 +5,9 @@ class SiteSetting::Policy::SettingsAreNotDeprecated < Service::PolicyBase
 
   def call
     @hard_deprecations =
-      params.settings.keys.filter_map do |id|
+      params.settings.filter_map do |setting|
         SiteSettings::DeprecatedSettings::SETTINGS.find do |old_name, new_name, override, _|
-          if old_name.to_sym == id
+          if old_name.to_sym == setting.name
             if override
               options.overridden_setting_names[old_name.to_sym] = new_name
               break
diff --git a/app/services/site_setting/policy/settings_are_unshadowed_globally.rb b/app/services/site_setting/policy/settings_are_unshadowed_globally.rb
index 2c850618a9f..d987abacd91 100644
--- a/app/services/site_setting/policy/settings_are_unshadowed_globally.rb
+++ b/app/services/site_setting/policy/settings_are_unshadowed_globally.rb
@@ -4,7 +4,7 @@ class SiteSetting::Policy::SettingsAreUnshadowedGlobally < Service::PolicyBase
   delegate :options, :params, to: :context
 
   def call
-    @hidden_settings = params.settings.keys.select(&method(:validate_setting))
+    @hidden_settings = params.settings.map(&:name).select(&method(:validate_setting))
     @hidden_settings.empty?
   end
 
diff --git a/app/services/site_setting/policy/settings_are_visible.rb b/app/services/site_setting/policy/settings_are_visible.rb
index 4bb6ee9e87b..d210d56e623 100644
--- a/app/services/site_setting/policy/settings_are_visible.rb
+++ b/app/services/site_setting/policy/settings_are_visible.rb
@@ -4,7 +4,7 @@ class SiteSetting::Policy::SettingsAreVisible < Service::PolicyBase
   delegate :options, :params, to: :context
 
   def call
-    @hidden_settings = params.settings.keys.select(&method(:validate_setting))
+    @hidden_settings = params.settings.map(&:name).select(&method(:validate_setting))
     @hidden_settings.empty?
   end
 
diff --git a/app/services/site_setting/policy/values_are_valid.rb b/app/services/site_setting/policy/values_are_valid.rb
index 5d325696717..5a29379c077 100644
--- a/app/services/site_setting/policy/values_are_valid.rb
+++ b/app/services/site_setting/policy/values_are_valid.rb
@@ -15,10 +15,9 @@ class SiteSetting::Policy::ValuesAreValid < Service::PolicyBase
   private
 
   def validate_setting(setting)
-    setting_name, setting_value = setting
-    setting_type = SiteSetting.type_supervisor.get_type(setting_name)
+    setting_type = SiteSetting.type_supervisor.get_type(setting.name)
     begin
-      SiteSetting.type_supervisor.validate_value(setting_name, setting_type, setting_value)
+      SiteSetting.type_supervisor.validate_value(setting.name, setting_type, setting.value)
       nil
     rescue Discourse::InvalidParameters => e
       e.message
diff --git a/app/services/site_setting/update.rb b/app/services/site_setting/update.rb
index 97c02aa93bd..7a5956240d6 100644
--- a/app/services/site_setting/update.rb
+++ b/app/services/site_setting/update.rb
@@ -3,6 +3,8 @@
 class SiteSetting::Update
   include Service::Base
 
+  Setting = Struct.new(:name, :value, :backfill, :change)
+
   options do
     attribute :allow_changing_hidden, :array, default: []
     attribute :overridden_setting_names, default: {}
@@ -14,32 +16,40 @@ class SiteSetting::Update
     attribute :settings
 
     before_validation do
-      self.settings = self.settings.to_a.map { |key, value| [key.to_sym, value.to_s.strip] }.to_h
+      self.settings =
+        self.settings.to_a.map do |setting|
+          Setting.new(
+            setting[:setting_name].to_sym,
+            setting[:value].to_s.strip,
+            !!setting[:backfill],
+            nil,
+          )
+        end
     end
 
     validates :settings, presence: true
 
     after_validation do
       self.settings =
-        self
-          .settings
-          .map do |setting_name, value|
-            value =
-              case SiteSetting.type_supervisor.get_type(setting_name)
-              when :integer
-                value.tr("^-0-9", "").to_i
-              when :file_size_restriction
-                value.tr("^0-9", "").to_i
-              when :uploaded_image_list
-                value.blank? ? "" : Upload.get_from_urls(value.split("|")).to_a
-              when :upload
-                Upload.get_from_url(value) || ""
-              else
-                value
-              end
-            [setting_name, value]
-          end
-          .to_h
+        self.settings.map do |setting|
+          raw_value = setting.value
+
+          setting.value =
+            case SiteSetting.type_supervisor.get_type(setting.name)
+            when :integer
+              raw_value.tr("^-0-9", "").to_i
+            when :file_size_restriction
+              raw_value.tr("^0-9", "").to_i
+            when :uploaded_image_list
+              raw_value.blank? ? "" : Upload.get_from_urls(raw_value.split("|")).to_a
+            when :upload
+              Upload.get_from_url(raw_value) || ""
+            else
+              raw_value
+            end
+
+          setting
+        end
     end
   end
 
@@ -49,7 +59,11 @@ class SiteSetting::Update
   policy :settings_are_visible, class_name: SiteSetting::Policy::SettingsAreVisible
   policy :settings_are_configurable, class_name: SiteSetting::Policy::SettingsAreConfigurable
   policy :values_are_valid, class_name: SiteSetting::Policy::ValuesAreValid
-  transaction { step :save }
+
+  transaction do
+    step :save
+    step :backfill
+  end
 
   private
 
@@ -58,12 +72,29 @@ class SiteSetting::Update
   end
 
   def save(params:, options:, guardian:)
-    params.settings.each do |setting_name, value|
-      SiteSetting.set_and_log(
-        options.overridden_setting_names[setting_name] || setting_name,
-        value,
-        guardian.user,
+    params.settings.each do |setting|
+      setting.change =
+        SiteSetting.set_and_log(
+          options.overridden_setting_names[setting.name] || setting.name,
+          setting.value,
+          guardian.user,
+        )
+    end
+  end
+
+  def backfill(params:)
+    params.settings.each do |setting|
+      next if !setting.backfill || !default_user_preference?(setting)
+
+      SiteSettingUpdateExistingUsers.call(
+        setting.name.to_s,
+        setting.change.new_value,
+        setting.change.previous_value,
       )
     end
   end
+
+  def default_user_preference?(setting)
+    SiteSetting::DEFAULT_USER_PREFERENCES.include?(setting.name.to_s)
+  end
 end
diff --git a/lib/tasks/javascript.rake b/lib/tasks/javascript.rake
index 07cd09c3c33..1bf1e3f3597 100644
--- a/lib/tasks/javascript.rake
+++ b/lib/tasks/javascript.rake
@@ -168,6 +168,8 @@ task "javascript:update_constants" => :environment do
 
     export const SITE_SETTING_REQUIRES_CONFIRMATION_TYPES = #{SiteSettings::TypeSupervisor::REQUIRES_CONFIRMATION_TYPES.to_json};
 
+    export const DEFAULT_USER_PREFERENCES = #{SiteSetting::DEFAULT_USER_PREFERENCES.to_json};
+
     export const MAX_UNOPTIMIZED_CATEGORIES = #{CategoryList::MAX_UNOPTIMIZED_CATEGORIES};
 
     export const USER_FIELD_FLAGS = #{UserField::FLAG_ATTRIBUTES};
diff --git a/spec/services/site_setting/update_spec.rb b/spec/services/site_setting/update_spec.rb
index 01b7097944f..6d45b830644 100644
--- a/spec/services/site_setting/update_spec.rb
+++ b/spec/services/site_setting/update_spec.rb
@@ -10,7 +10,8 @@ RSpec.describe SiteSetting::Update do
 
     fab!(:admin)
     let(:params) { { settings: } }
-    let(:settings) { { setting_name => new_value } }
+    let(:settings) { [{ setting_name: setting_name, value: new_value, backfill: backfill }] }
+    let(:backfill) { false }
     let(:options) { { allow_changing_hidden: } }
     let(:dependencies) { { guardian: } }
     let(:setting_name) { :title }
@@ -114,7 +115,12 @@ RSpec.describe SiteSetting::Update do
     end
 
     context "when one setting is having invalid value" do
-      let(:settings) { { title: "hello this is title", default_categories_watching: "999999" } }
+      let(:settings) do
+        [
+          { setting_name: "title", value: "hello this is title" },
+          { setting_name: "default_categories_watching", value: "999999" },
+        ]
+      end
 
       it { is_expected.to fail_a_policy(:values_are_valid) }
 
@@ -122,5 +128,21 @@ RSpec.describe SiteSetting::Update do
         expect { result }.not_to change { SiteSetting.title }
       end
     end
+
+    context "when backfill is requested" do
+      let(:settings) do
+        [
+          { setting_name: "default_hide_profile", value: true, backfill: true },
+          { setting_name: "default_hide_presence", value: true, backfill: false },
+          { setting_name: "title", value: true, backfill: true },
+        ]
+      end
+
+      it "calls the relevant class for backfill" do
+        SiteSettingUpdateExistingUsers.expects(:call).once.with("default_hide_profile", true, false)
+
+        result
+      end
+    end
   end
 end