diff --git a/Gemfile b/Gemfile
index 1ba6a8d68c..0df173b631 100644
--- a/Gemfile
+++ b/Gemfile
@@ -20,8 +20,6 @@ gem "activejob-uniqueness"
 # Needed for XML serialization of ActiveRecord::Base
 gem 'activemodel-serializers-xml'
 
-gem 'protected_attributes_continued', '~> 1.9.0'
-
 gem 'rails-observers'
 
 gem 'strong_migrations', '~> 2.1.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index e805cbf169..efba18e773 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -618,8 +618,6 @@ GEM
       bigdecimal
       logger
       rb_sys (~> 0.9.117)
-    protected_attributes_continued (1.9.0)
-      activemodel (>= 5.0)
     pry (0.15.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
@@ -1101,7 +1099,6 @@ DEPENDENCIES
   prawn
   prawn-svg
   prawn-table!
-  protected_attributes_continued (~> 1.9.0)
   pry-byebug (>= 3.11.0)
   pry-doc (>= 0.8)
   pry-rails
diff --git a/app/events/applications/application_deleted_event.rb b/app/events/applications/application_deleted_event.rb
index 46afefb366..6657e47fd7 100644
--- a/app/events/applications/application_deleted_event.rb
+++ b/app/events/applications/application_deleted_event.rb
@@ -5,7 +5,7 @@ class Applications::ApplicationDeletedEvent < ApplicationRelatedEvent
   # @param [Cinstance] application
   # :reek:NilCheck but proxy can be nil at this point
   def self.create(application)
-    service = application.service || Service.new({id: application.service_id}, without_protection: true)
+    service = application.service || Service.new(id: application.service_id)
     new(
       application: MissingModel::MissingApplication.new(id: application.id),
       service_backend_id: service.backend_id,
diff --git a/app/events/zync_event.rb b/app/events/zync_event.rb
index 3061958838..31b6bede09 100644
--- a/app/events/zync_event.rb
+++ b/app/events/zync_event.rb
@@ -70,7 +70,7 @@ def self.type_for(model)
   def non_persisted_dependencies
     case record
     when Proxy, Cinstance
-      [Service.new({id: data[:service_id]}, without_protection: true)]
+      [Service.new(id: data[:service_id])]
     else
       NONE
     end
diff --git a/app/lib/backend_api_logic/service_extension.rb b/app/lib/backend_api_logic/service_extension.rb
index 64388c99ca..47a624ee2b 100644
--- a/app/lib/backend_api_logic/service_extension.rb
+++ b/app/lib/backend_api_logic/service_extension.rb
@@ -33,7 +33,11 @@ def backend_api_config
       end
 
       def backend_api
-        @backend_api ||= backend_api_configs.first&.backend_api || account.backend_apis.build(system_name: service_system_name, name: "#{service_name} Backend", description: "Backend of #{service_name}")
+        # Return early if we already have a persisted backend_api
+        return @backend_api if @backend_api&.persisted?
+
+        # Try to get backend_api from backend_api_configs, or keep the memoized unpersisted one, or build a new one
+        @backend_api = backend_api_configs.first&.backend_api || @backend_api || build_backend_api
       end
 
       def update!(attrs = {})
@@ -52,6 +56,18 @@ def update(attrs = {})
       rescue ActiveRecord::RecordInvalid
         false
       end
+
+      private
+
+      def build_backend_api
+        # Build without adding to association to avoid polluting it with unpersisted records
+        BackendApi.new(
+          account: account,
+          system_name: service_system_name,
+          name: "#{service_name} Backend",
+          description: "Backend of #{service_name}"
+        )
+      end
     end
 
     def backend_api_proxy
diff --git a/app/lib/fields/fields.rb b/app/lib/fields/fields.rb
index d207e8828f..668436a863 100644
--- a/app/lib/fields/fields.rb
+++ b/app/lib/fields/fields.rb
@@ -124,7 +124,7 @@ def initialize(attributes = nil, *args)
     # otherwise it raises exception on unknown (extra) fields
     # check http://api.rubyonrails.org/classes/ActiveRecord/AttributeAssignment.html#method-i-assign_attributes
 
-    def assign_attributes(extra_attributes, options = {})
+    def assign_attributes(extra_attributes)
       # dup the fields because we are mutating them (params hash)
       attributes = extra_attributes.present? ? extra_attributes.dup : {}
 
@@ -135,7 +135,7 @@ def assign_attributes(extra_attributes, options = {})
         self.extra_fields = fields_attributes
       end
 
-      super(attributes, options)
+      super(attributes)
     end
 
     alias attributes= assign_attributes
diff --git a/app/lib/fields/provider.rb b/app/lib/fields/provider.rb
index 9b00cb5fff..a32be3bfda 100644
--- a/app/lib/fields/provider.rb
+++ b/app/lib/fields/provider.rb
@@ -11,9 +11,8 @@ def initialize(provider)
       def for(klass)
         columns = klass.column_names
         defined = fields_definitions.by_target(klass.name.underscore).map(&:name)
-        protected =  klass.protected_attributes.to_a
 
-        ((columns + defined) - protected).uniq
+        (columns + defined).uniq
       end
 
       protected
diff --git a/app/lib/finance/billing.rb b/app/lib/finance/billing.rb
index ff9acf7fd1..62235a9c84 100644
--- a/app/lib/finance/billing.rb
+++ b/app/lib/finance/billing.rb
@@ -8,7 +8,7 @@ def initialize(invoice)
 
     def create_line_item(params)
       bill do
-        @invoice.line_items.create(params, {without_protection: true})
+        @invoice.line_items.create(params)
       end
     rescue Invoice::InvalidInvoiceStateException
       line_item_with_error(params, :invalid_invoice_state)
@@ -18,7 +18,7 @@ def create_line_item(params)
 
     def create_line_item!(params)
       bill do
-        @invoice.line_items.create!(params, {without_protection: true})
+        @invoice.line_items.create!(params)
       end
     end
 
@@ -37,7 +37,7 @@ def bill
     end
 
     def line_item_with_error(params, error_type)
-      LineItem.new(params, {without_protection: true}).tap do |line_item|
+      LineItem.new(params).tap do |line_item|
         line_item.errors.add(:base, error_type.to_sym)
       end
     end
diff --git a/app/lib/logic/cms.rb b/app/lib/logic/cms.rb
index 78f84bcf8e..e0992614aa 100644
--- a/app/lib/logic/cms.rb
+++ b/app/lib/logic/cms.rb
@@ -64,7 +64,7 @@ def cms_toolbar_intro_visible?
       end
 
       def create_cms_assets
-        self.builtin_sections.create!({ title: 'Root', system_name: 'root', parent_id: nil }, without_protection: true)
+        self.builtin_sections.create!(title: 'Root', system_name: 'root', parent_id: nil)
         # TODO: add SimpleLayout logic here
       end
     end
diff --git a/app/lib/signup/impersonation_admin_builder.rb b/app/lib/signup/impersonation_admin_builder.rb
index 69d36fa028..14f6d8b38b 100644
--- a/app/lib/signup/impersonation_admin_builder.rb
+++ b/app/lib/signup/impersonation_admin_builder.rb
@@ -6,14 +6,12 @@ def self.build(account:)
       config = ThreeScale.config.impersonation_admin
       username = config[:username]
       impersonation_admin = account.users.new(
-        {
-          username: username,
-          email: "#{username}+#{account.internal_domain}@#{config[:domain]}",
-          first_name: '3scale',
-          last_name: 'Admin',
-          state: 'active'
-        },
-        without_protection: true)
+        username: username,
+        email: "#{username}+#{account.internal_domain}@#{config[:domain]}",
+        first_name: '3scale',
+        last_name: 'Admin',
+        state: 'active'
+      )
       impersonation_admin.role = :admin
       impersonation_admin.signup_type = :minimal
       impersonation_admin
diff --git a/app/models/account_setting.rb b/app/models/account_setting.rb
index 741cbd5fce..2902f6284d 100644
--- a/app/models/account_setting.rb
+++ b/app/models/account_setting.rb
@@ -11,9 +11,6 @@ def self.find_sti_class(type_name)
     self
   end
 
-  # TODO: remove attr_accessible once protected_attributes_continued gem is removed
-  attr_accessible :type, :value, :account, :tenant_id
-
   belongs_to :account, inverse_of: :account_settings
 
   audited associated_with: :account
diff --git a/app/models/cms/template.rb b/app/models/cms/template.rb
index 20206459c0..02895ecdea 100644
--- a/app/models/cms/template.rb
+++ b/app/models/cms/template.rb
@@ -94,7 +94,7 @@ def current
 
   def build_version(attrs = {})
     version = versions.build
-    version.assign_attributes(version_attributes.merge(attrs), :without_protection => true)
+    version.assign_attributes(version_attributes.merge(attrs))
     version
   end
 
diff --git a/app/models/cms/template/version.rb b/app/models/cms/template/version.rb
index 3057a8dc32..f3574c43f5 100644
--- a/app/models/cms/template/version.rb
+++ b/app/models/cms/template/version.rb
@@ -32,10 +32,8 @@ def diff(other)
   end
 
   def revert_attributes
-    accessible = template.class.accessible_attributes.delete('draft').add('updated_at').add('updated_by')
-
-    accessible << state.to_s
-    attributes.slice *accessible
+    accessible = [:updated_at, :updated_by, state.to_s]
+    attributes.slice(*accessible)
   end
 
 end
diff --git a/app/models/contract.rb b/app/models/contract.rb
index 308eb9441b..7db00465d9 100644
--- a/app/models/contract.rb
+++ b/app/models/contract.rb
@@ -4,7 +4,7 @@ class Contract < ApplicationRecord
   # https://github.com/collectiveidea/audited/blob/f03c5b5d1717f2ebec64032d269316dc74476056/lib/audited/auditor.rb#L305-L311
   self.table_name = 'cinstances'
 
-  audited allow_mass_assignment: true
+  audited
 
   # FIXME: This class should be an abstract class I think, but doing so makes plenty of tests fail
   # self.abstract_class = true
diff --git a/app/models/feature.rb b/app/models/feature.rb
index efd7c1a8e2..092250d419 100644
--- a/app/models/feature.rb
+++ b/app/models/feature.rb
@@ -2,7 +2,7 @@ class Feature < ApplicationRecord
 
   self.background_deletion = [:features_plans]
 
-  audited :allow_mass_assignment => true
+  audited
 
   #TODO: these need tests
   #OPTIMIZE subclassing a better solution for these 2
diff --git a/app/models/finance/billing_strategy.rb b/app/models/finance/billing_strategy.rb
index 25a89e7602..869d46845e 100644
--- a/app/models/finance/billing_strategy.rb
+++ b/app/models/finance/billing_strategy.rb
@@ -11,7 +11,7 @@ class << self
     prepend NonAuditedColumns
   end
 
-  audited :allow_mass_assignment => true
+  audited
 
   attr_reader :failed_buyers
 
diff --git a/app/models/invoice.rb b/app/models/invoice.rb
index d4a73d3386..b8c2874891 100644
--- a/app/models/invoice.rb
+++ b/app/models/invoice.rb
@@ -14,7 +14,7 @@ class Invoice < ApplicationRecord
   enum creation_type: {manual: 'manual', background: 'background'}
 
   include AfterCommitQueue
-  audited :allow_mass_assignment => true
+  audited
   has_associated_audits
 
   class InvalidInvoiceStateException < RuntimeError; end
diff --git a/app/models/line_item.rb b/app/models/line_item.rb
index 0f7eee6fd2..c3f428c72a 100644
--- a/app/models/line_item.rb
+++ b/app/models/line_item.rb
@@ -5,7 +5,7 @@ class LineItem < ApplicationRecord
   belongs_to :contract, polymorphic: true
   belongs_to :metric, inverse_of: :line_items
 
-  audited associated_with: :invoice, allow_mass_assignment: true
+  audited associated_with: :invoice
 
   validates :name, :description, :type, :contract_type, length: { maximum: 255 }
   validates :type, inclusion: {in: [LineItem::PlanCost, LineItem::VariableCost].flat_map { |klass| [klass, klass.to_s]}, allow_blank: true}
diff --git a/app/models/mail_dispatch_rule.rb b/app/models/mail_dispatch_rule.rb
index 800933ada2..61a4239f6b 100644
--- a/app/models/mail_dispatch_rule.rb
+++ b/app/models/mail_dispatch_rule.rb
@@ -10,14 +10,15 @@ def self.fetch_with_retry!(options, &block)
     retries = 0
 
     begin
-      MailDispatchRule.find_or_create_by!(options, &block)
+      # Use find_by + create! directly to avoid transaction wrapper from create_or_find_by!
+      # This preserves the old behavior from protected_attributes_continued gem
+      # where records created in the block are committed even if the outer create fails
+      find_by(options) || create!(options, &block)
     rescue ActiveRecord::RecordNotUnique
-      if retries > 10
-        raise
-      else
-        retries += 1
-        retry
-      end
+      raise if retries > 10
+
+      retries += 1
+      retry
     end
   end
 end
diff --git a/app/models/metric.rb b/app/models/metric.rb
index 2e0c822d33..ff634d0dce 100644
--- a/app/models/metric.rb
+++ b/app/models/metric.rb
@@ -21,7 +21,7 @@ class Metric < ApplicationRecord
 
   has_many :proxy_rules, :dependent => :destroy, inverse_of: :metric
 
-  audited :allow_mass_assignment => true
+  audited
   has_system_name uniqueness_scope: %i[owner_type owner_id], human_name: :friendly_name
 
   acts_as_tree
diff --git a/app/models/payment_detail.rb b/app/models/payment_detail.rb
index 4600bd5f8d..d503b1a667 100644
--- a/app/models/payment_detail.rb
+++ b/app/models/payment_detail.rb
@@ -10,7 +10,7 @@ class PaymentDetail < ApplicationRecord
 
   belongs_to :account
 
-  audited allow_mass_assignment: true
+  audited
 
   validates :credit_card_partial_number, length: { :maximum => 4,
                                                    :allow_blank => true,
diff --git a/app/models/plan.rb b/app/models/plan.rb
index 0a915e9d3a..bb4e86b48c 100644
--- a/app/models/plan.rb
+++ b/app/models/plan.rb
@@ -16,7 +16,7 @@ class PeriodRangeCalculationError < StandardError; end
 
   has_system_name :uniqueness_scope => [ :type, :issuer_id, :issuer_type ]
 
-  audited :allow_mass_assignment => true
+  audited
   acts_as_list scope: %i[issuer_id issuer_type]
 
   # There is a race condition here, the record gets deleted but the callbacks were not triggered yet
diff --git a/app/models/pricing_rule.rb b/app/models/pricing_rule.rb
index f8b631968f..23f84d777b 100644
--- a/app/models/pricing_rule.rb
+++ b/app/models/pricing_rule.rb
@@ -1,6 +1,6 @@
 class PricingRule < ApplicationRecord
   DECIMALS = 4
-  audited :allow_mass_assignment => true
+  audited
 
   belongs_to :plan
   belongs_to :metric
diff --git a/app/models/provider_constraints.rb b/app/models/provider_constraints.rb
index f7c602bf90..af72015db8 100644
--- a/app/models/provider_constraints.rb
+++ b/app/models/provider_constraints.rb
@@ -1,7 +1,7 @@
 class ProviderConstraints < ApplicationRecord
   NO_LIMIT = Float::INFINITY
 
-  audited allow_mass_assignment: true
+  audited
 
   belongs_to :provider, class_name: 'Account'
 
diff --git a/app/models/settings.rb b/app/models/settings.rb
index 17ee8c8c3f..e765f88e26 100644
--- a/app/models/settings.rb
+++ b/app/models/settings.rb
@@ -2,7 +2,7 @@ class Settings < ApplicationRecord
   include Symbolize
   belongs_to :account, inverse_of: :settings
 
-  audited allow_mass_assignment: true
+  audited
 
   validates :product, inclusion: { in: %w[connect enterprise].freeze }
   validates :change_account_plan_permission, :change_service_plan_permission, inclusion: { in: %w[request none credit_card request_credit_card direct].freeze }
@@ -37,8 +37,8 @@ def approval_required_disabled?
     not_custom_account_plans.size > 1 && account_plans_ui_visible?
   end
 
-  def assign_attributes(attrs, options = {})
-    super(sanitize_attributes(attrs), options)
+  def assign_attributes(attrs)
+    super(sanitize_attributes(attrs))
   end
 
   def update(attrs)
diff --git a/app/services/finance/stripe_payment_intent_update_service.rb b/app/services/finance/stripe_payment_intent_update_service.rb
index 91cf1416eb..3248b6892f 100644
--- a/app/services/finance/stripe_payment_intent_update_service.rb
+++ b/app/services/finance/stripe_payment_intent_update_service.rb
@@ -41,6 +41,6 @@ def create_payment_transaction
       params: source_object
     }
 
-    payment_transactions.create(attributes, without_protection: true)
+    payment_transactions.create(attributes)
   end
 end
diff --git a/app/services/service_discovery/import_cluster_definitions_service.rb b/app/services/service_discovery/import_cluster_definitions_service.rb
index 16ea305b08..940cf4ea73 100644
--- a/app/services/service_discovery/import_cluster_definitions_service.rb
+++ b/app/services/service_discovery/import_cluster_definitions_service.rb
@@ -91,7 +91,7 @@ def import_cluster_active_docs_to(service)
     end
 
     def build_api_doc_service(service)
-      service.api_docs_services.build({ name: cluster_service.name, published: true, discovered: true }, without_protection: true)
+      service.api_docs_services.build(name: cluster_service.name, published: true, discovered: true)
     end
 
     def valid_cluster_service_spec?(service)
diff --git a/app/workers/audited_worker.rb b/app/workers/audited_worker.rb
index 3c2fd8ff67..4a37c91618 100644
--- a/app/workers/audited_worker.rb
+++ b/app/workers/audited_worker.rb
@@ -3,7 +3,7 @@ class AuditedWorker
 
   def perform(attributes)
     audit = Audited.audit_class.new
-    audit.assign_attributes(attributes, without_protection: true) # Rails 4 can remove the option
+    audit.assign_attributes(attributes)
     audit.save!
   end
 end
diff --git a/app/workers/backend_delete_service_worker.rb b/app/workers/backend_delete_service_worker.rb
index 93e9e01ac4..e79752b767 100644
--- a/app/workers/backend_delete_service_worker.rb
+++ b/app/workers/backend_delete_service_worker.rb
@@ -11,7 +11,7 @@ def perform(event_id)
     event = EventStore::Repository.find_event!(event_id)
     service_id = event.service_id
     ThreeScale::Core::Service.delete_stats(service_id, {})
-    service = Service.new({id: service_id}, without_protection: true)
+    service = Service.new(id: service_id)
     service.delete_backend_service
   rescue ActiveRecord::RecordNotFound => exception
     System::ErrorReporting.report_error(exception, parameters: {event_id: event_id})
diff --git a/config/application.rb b/config/application.rb
index 98c52c41d3..bcca29a16a 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -131,8 +131,6 @@ def try_config_for(*args)
 
     config.logger = ActiveSupport::TaggedLogging.new(ActiveSupport::Logger.new(STDOUT)) if ENV['RAILS_LOG_TO_STDOUT'].present?
 
-    config.active_record.whitelist_attributes = false
-
     config.boot_time = Time.now
 
     # Configuration for the application, engines, and railties goes here.
diff --git a/config/initializers/protected_attributes_hacks.rb b/config/initializers/protected_attributes_hacks.rb
deleted file mode 100644
index 10159ab760..0000000000
--- a/config/initializers/protected_attributes_hacks.rb
+++ /dev/null
@@ -1,27 +0,0 @@
-# OMG!!!! Such bad citizen!!!
-# https://github.com/westonganger/protected_attributes_continued/blob/master/lib/active_record/mass_assignment_security/relation.rb
-# They just reopened Rails module instead of using their proper module ...
-# Thus they totally short circuit all the other modules, not really good with integration with other gems like BabySqueel
-
-module ProtectedAttributesHacks
-  module QueryMethods
-    def sanitize_forbidden_attributes(attributes)
-      if model._uses_mass_assignment_security
-        # We just permit everything
-        super(attributes.respond_to?(:permit!) ? attributes.dup.permit! : attributes)
-      else
-        super
-      end
-    end
-  end
-end
-
-ActiveSupport.on_load(:active_record) do
-  ActiveRecord::QueryMethods.module_eval do
-    remove_method :sanitize_forbidden_attributes
-  end
-
-  ActiveRecord::Relation.class_eval do
-    include ProtectedAttributesHacks::QueryMethods
-  end
-end
diff --git a/config/initializers/state_machines_protected_attributes.rb b/config/initializers/state_machines_protected_attributes.rb
deleted file mode 100644
index e8c02cbb6b..0000000000
--- a/config/initializers/state_machines_protected_attributes.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-# frozen_string_literal: true
-module StateMachines
-  module Integrations
-    module ActiveRecord
-      if defined?(ProtectedAttributes)
-        def define_state_initializer
-          define_helper :instance, <<-end_eval, __FILE__, __LINE__ + 1
-            def initialize(attributes = nil, options = {})
-              super(attributes, options) do |*args|
-                self.class.state_machines.initialize_states(self, {}, attributes || {})
-                yield(*args) if block_given?
-              end
-            end
-          end_eval
-        end
-      end
-    end
-  end
-end
diff --git a/lib/developer_portal/test/dummy/config/application.rb b/lib/developer_portal/test/dummy/config/application.rb
index c472c327d2..30c44519a0 100644
--- a/lib/developer_portal/test/dummy/config/application.rb
+++ b/lib/developer_portal/test/dummy/config/application.rb
@@ -43,12 +43,6 @@ class Application < Rails::Application
     # like if you have constraints or database-specific column types
     # config.active_record.schema_format = :sql
 
-    # Enforce whitelist mode for mass assignment.
-    # This will create an empty whitelist of attributes available for mass-assignment for all models
-    # in your app. As such, your models will need to explicitly whitelist or blacklist accessible
-    # parameters by using an attr_accessible or attr_protected declaration.
-    config.active_record.whitelist_attributes = true
-
     # Enable the asset pipeline
     config.assets.enabled = true
 
diff --git a/lib/developer_portal/test/dummy/config/environments/development.rb b/lib/developer_portal/test/dummy/config/environments/development.rb
index 82c74d1541..4db6d3646f 100644
--- a/lib/developer_portal/test/dummy/config/environments/development.rb
+++ b/lib/developer_portal/test/dummy/config/environments/development.rb
@@ -22,9 +22,6 @@
   # Only use best-standards-support built into browsers
   config.action_dispatch.best_standards_support = :builtin
 
-  # Raise exception on mass assignment protection for Active Record models
-  config.active_record.mass_assignment_sanitizer = :strict
-
   # Log the query plan for queries taking more than this (works
   # with SQLite, MySQL, and PostgreSQL)
   config.active_record.auto_explain_threshold_in_seconds = 0.5
diff --git a/lib/developer_portal/test/dummy/config/environments/test.rb b/lib/developer_portal/test/dummy/config/environments/test.rb
index f10c53c46d..70d1275f1d 100644
--- a/lib/developer_portal/test/dummy/config/environments/test.rb
+++ b/lib/developer_portal/test/dummy/config/environments/test.rb
@@ -29,9 +29,6 @@
   # ActionMailer::Base.deliveries array.
   config.action_mailer.delivery_method = :test
 
-  # Raise exception on mass assignment protection for Active Record models
-  config.active_record.mass_assignment_sanitizer = :strict
-
   # Print deprecation notices to the stderr
   config.active_support.deprecation = :stderr
 end
diff --git a/test/integration/admin/api_docs/account_api_docs_controller_test.rb b/test/integration/admin/api_docs/account_api_docs_controller_test.rb
index 57b0d88825..2bee96fc33 100644
--- a/test/integration/admin/api_docs/account_api_docs_controller_test.rb
+++ b/test/integration/admin/api_docs/account_api_docs_controller_test.rb
@@ -19,7 +19,7 @@ class ProviderLoggedInTest < Admin::ApiDocs::AccountApiDocsControllerTest
       get preview_admin_api_docs_service_path(api_docs_service)
       assert_account_active_docs_menus
 
-      api_docs_service.update({service_id: service.id}, without_protection: true)
+      api_docs_service.update({service_id: service.id})
       get preview_admin_api_docs_service_path(api_docs_service)
       assert_redirected_to preview_admin_service_api_doc_path(service, api_docs_service)
     end
@@ -28,7 +28,7 @@ class ProviderLoggedInTest < Admin::ApiDocs::AccountApiDocsControllerTest
       get edit_admin_api_docs_service_path(api_docs_service)
       assert_account_active_docs_menus
 
-      api_docs_service.update({service_id: service.id}, without_protection: true)
+      api_docs_service.update({service_id: service.id})
       get edit_admin_api_docs_service_path(api_docs_service)
       assert_redirected_to edit_admin_service_api_doc_path(service, api_docs_service)
     end
diff --git a/test/integration/services/finance/billing_service_integration_test.rb b/test/integration/services/finance/billing_service_integration_test.rb
index b467f28aa8..db5a40e3bd 100644
--- a/test/integration/services/finance/billing_service_integration_test.rb
+++ b/test/integration/services/finance/billing_service_integration_test.rb
@@ -48,7 +48,7 @@ class ConcurrentBillingCalls < Finance::BillingServiceIntegrationTest
       Finance::BillingService.call!(buyer.id, provider_account_id: provider.id, now: invoice.due_on)
       assert_equal "unpaid", invoice.reload.state
 
-      invoice.update({ last_charging_retry: invoice.last_charging_retry - 4.days }, without_protection: true)
+      invoice.update(last_charging_retry: invoice.last_charging_retry - 4.days)
       Finance::BillingService.call!(buyer.id, provider_account_id: provider.id, now: invoice.due_on)
       assert_equal "unpaid", invoice.reload.state
 
diff --git a/test/test_helpers/provider.rb b/test/test_helpers/provider.rb
index 460143026a..7d0a9a32e5 100644
--- a/test/test_helpers/provider.rb
+++ b/test/test_helpers/provider.rb
@@ -80,15 +80,15 @@ def create_a_complete_provider
           FactoryBot.create(:keycloak_self_authentication_provider, account: provider)
           FactoryBot.create(:github_authentication_provider, account: provider)
           FactoryBot.create(:redhat_customer_portal_authentication_provider, account: provider)
-          provider.authentication_providers.create!({ type: "AuthenticationProvider::Custom", client_id: 'id', client_secret: 'secret', site: 'http://example.com', account: provider }, { without_protection: true })
-          provider.authentication_providers.create!({ type: "AuthenticationProvider::ServiceDiscoveryProvider", client_id: 'id', client_secret: 'secret', site: 'http://example.com', account: provider }, {without_protection: true })
+          provider.authentication_providers.create!(type: "AuthenticationProvider::Custom", client_id: 'id', client_secret: 'secret', site: 'http://example.com', account: provider)
+          provider.authentication_providers.create!(type: "AuthenticationProvider::ServiceDiscoveryProvider", client_id: 'id', client_secret: 'secret', site: 'http://example.com', account: provider)
 
           forum = FactoryBot.create(:forum, account: provider)
           topic = FactoryBot.create(:topic, user: provider.admin_user, forum:)
           FactoryBot.create(:topic_category, forum:)
           FactoryBot.create(:post, user: provider.admin_user, forum:, topic:)
-          UserTopic.create({user: provider.admin_user, topic:}, {without_protection: true})
-          Moderatorship.create({user: provider.admin_user, forum:}, {without_protection: true})
+          UserTopic.create(user: provider.admin_user, topic: topic)
+          Moderatorship.create(user: provider.admin_user, forum: forum)
 
           Configuration::Value.create(configurable: provider, name: "foo", value: "bar")
 
@@ -106,7 +106,7 @@ def create_a_complete_provider
           LatestForumPostsPortlet.create!(provider:, portlet_type: 'LatestForumPostsPortlet', system_name: 'name', posts: forum.posts.count)
           TableOfContentsPortlet.create!(provider:, portlet_type: 'TableOfContentsPortlet', system_name: 'name', section_id: provider.provided_sections.first.id)
           CMS::Redirect.new.tap do |redirect|
-            redirect.assign_attributes({source: "a", target: "b", provider:}, {without_protection: true})
+            redirect.assign_attributes(source: "a", target: "b", provider: provider)
           end.save!
 
           provider
diff --git a/test/unit/api_docs/service_test.rb b/test/unit/api_docs/service_test.rb
index 009363d00a..a864c70672 100644
--- a/test/unit/api_docs/service_test.rb
+++ b/test/unit/api_docs/service_test.rb
@@ -574,7 +574,7 @@ def teardown
     refute api_doc.valid?
     assert_includes api_doc.errors[:service], 'not found'
 
-    api_doc = account.api_docs_services.new(valid_attributes.merge({service_id: service.id + 1000}), without_protection: true)
+    api_doc = account.api_docs_services.new(valid_attributes.merge(service_id: service.id + 1000))
     refute api_doc.valid?
     assert_includes api_doc.errors[:service], 'not found'
   end
diff --git a/test/unit/backend_api_logic/service_extension_test.rb b/test/unit/backend_api_logic/service_extension_test.rb
index a02199cfea..57b984e44c 100644
--- a/test/unit/backend_api_logic/service_extension_test.rb
+++ b/test/unit/backend_api_logic/service_extension_test.rb
@@ -36,5 +36,84 @@ class BackendApiProxy < ActiveSupport::TestCase
 
       assert_equal backend_api_config, service.backend_api_proxy.backend_api_config
     end
+
+    test '#backend_api returns backend_api from the first backend_api_configs, if persisted' do
+      service = FactoryBot.create(:simple_service)
+      backend_api = FactoryBot.create(:backend_api, account: service.account)
+      another_backend_api = FactoryBot.create(:backend_api, account: service.account)
+      FactoryBot.create(:backend_api_config, service: service, backend_api: backend_api, path: '/one')
+      FactoryBot.create(:backend_api_config, service: service, backend_api: another_backend_api, path: '/two')
+
+      assert_equal 2, service.reload.backend_api_configs.count
+
+      first_result = service.backend_api
+      assert_equal backend_api, first_result
+
+      # The second call returns the memoized instance
+      second_result = service.backend_api
+      assert_same first_result, second_result
+    end
+
+    test '#update! saves backend_api_config and backend_api for the service' do
+      service = FactoryBot.create(:simple_service)
+
+      # built on demand
+      backend_api = service.backend_api
+      assert_not backend_api.persisted?
+      assert_not service.backend_api_proxy.backend_api_config.persisted?
+
+      service.backend_api_proxy.update!(private_endpoint: 'https://api.example.com', path: '/backend-path')
+
+      # memoized instances, but now persisted
+      persisted_backend_api = service.backend_api
+
+      assert persisted_backend_api.persisted?
+      assert service.backend_api_proxy.backend_api_config.persisted?
+
+      assert_same backend_api, persisted_backend_api
+    end
+
+    test '#backend_api builds and memoizes unpersisted backend_api' do
+      service = FactoryBot.create(:simple_service)
+      proxy = service.backend_api_proxy
+
+      # First call builds unpersisted backend_api
+      first_call = proxy.backend_api
+      assert_not first_call.persisted?
+      assert_equal service.account, first_call.account
+      assert_equal service.system_name, first_call.system_name
+
+      # Second call returns the same memoized unpersisted instance
+      second_call = proxy.backend_api
+      assert_same first_call, second_call
+      assert_not second_call.persisted?
+    end
+
+    test '#backend_api_config memoizes across multiple calls' do
+      service = FactoryBot.create(:simple_service)
+      proxy = service.backend_api_proxy
+
+      first_call = proxy.backend_api_config
+      second_call = proxy.backend_api_config
+
+      assert_not first_call.persisted?
+      assert_not second_call.persisted?
+      assert_same first_call, second_call
+    end
+
+    test '#backend_api does not pollute account.backend_apis association with unpersisted records' do
+      service = FactoryBot.create(:simple_service)
+      account = service.account
+
+      initial_count = account.backend_apis.count
+
+      # Call backend_api which builds an unpersisted backend_api
+      backend_api = service.backend_api_proxy.backend_api
+      assert_not backend_api.persisted?
+
+      # Association should not include unpersisted record
+      assert_equal initial_count, account.backend_apis.count
+      assert_not_includes account.backend_apis, backend_api
+    end
   end
 end
diff --git a/test/unit/cinstance_test.rb b/test/unit/cinstance_test.rb
index 04abae07cb..6990986798 100644
--- a/test/unit/cinstance_test.rb
+++ b/test/unit/cinstance_test.rb
@@ -979,13 +979,13 @@ def setup
     end
 
     assert_no_difference(EventStore::Event.where(event_type: Applications::ApplicationUpdatedEvent.to_s).method(:count)) do
-      cinstance.update!({ first_traffic_at: 1.day.ago.round, first_daily_traffic_at: 1.day.ago.round }, without_protection: true)
+      cinstance.update!(first_traffic_at: 1.day.ago.round, first_daily_traffic_at: 1.day.ago.round)
     end
   end
 
   test 'ApplicationUpdatedEvent is created after an update when there are updated traffic and non-traffic attributes' do
     assert_difference(EventStore::Event.where(event_type: Applications::ApplicationUpdatedEvent.to_s).method(:count)) do
-      cinstance.update!({ name: 'mycinstance', first_traffic_at: 1.day.ago.round, first_daily_traffic_at: 1.day.ago.round }, without_protection: true)
+      cinstance.update!(name: 'mycinstance', first_traffic_at: 1.day.ago.round, first_daily_traffic_at: 1.day.ago.round)
     end
   end
 end
diff --git a/test/unit/mail_dispatch_rule_test.rb b/test/unit/mail_dispatch_rule_test.rb
index 1fbbcdeda3..4c05c1a73f 100644
--- a/test/unit/mail_dispatch_rule_test.rb
+++ b/test/unit/mail_dispatch_rule_test.rb
@@ -9,7 +9,7 @@ def test_fetch_with_retry
       expected.save!
     end
 
-    assert_equal expected , rule
+    assert_equal expected, rule
   end
 
   test 'is unique' do
diff --git a/test/unit/models_test.rb b/test/unit/models_test.rb
index ddd63c0141..c004e7bbde 100644
--- a/test/unit/models_test.rb
+++ b/test/unit/models_test.rb
@@ -72,7 +72,7 @@ class ModelsTest < ActiveSupport::TestCase
         next if column_sql_type.match(/\Acharacter varying\Z/)
         length = column_sql_type.match(/\(([\d]+)\)/)[1].to_i
 
-        object = model.new(options, without_protection: true)
+        object = model.new(options)
         object.send("#{column_name}=", 'a' * (length + 1))
         object.valid?
 
diff --git a/test/unit/tasks/services_test.rb b/test/unit/tasks/services_test.rb
index 626e1e2fa5..8a904f3515 100644
--- a/test/unit/tasks/services_test.rb
+++ b/test/unit/tasks/services_test.rb
@@ -16,7 +16,7 @@ class ServicesTest < ActiveSupport::TestCase
       default_service = FactoryBot.create(:simple_service)
       account = default_service.account
       another_service = FactoryBot.create(:simple_service, account: account)
-      account.update!({default_service_id: default_service.id}, without_protection: true)
+      account.update!({default_service_id: default_service.id})
       default_service.reload
 
       ThreeScale::Core::Service.expects(:make_default).with(another_service.backend_id)
@@ -35,9 +35,9 @@ class ServicesTest < ActiveSupport::TestCase
 
     test 'destroy_service raises ActiveRecord::RecordNotFound or StateMachines::InvalidTransition when the Account does not have another active Service' do
       default_service = FactoryBot.create(:simple_service)
-      default_service.account.update!({default_service_id: default_service.id}, without_protection: true)
+      default_service.account.update!({default_service_id: default_service.id})
       non_default_service = FactoryBot.create(:simple_service)
-      non_default_service.account.update!({default_service_id: nil}, without_protection: true)
+      non_default_service.account.update!({default_service_id: nil})
 
       assert_raise(ActiveRecord::RecordNotFound) do
         execute_rake_task 'services.rake', 'services:destroy_service', default_service.account.id, default_service.id
@@ -62,7 +62,7 @@ class ServicesTest < ActiveSupport::TestCase
       default_service = FactoryBot.create(:simple_service)
       account = default_service.account
       non_default_service = FactoryBot.create(:simple_service, account: account)
-      account.update!({default_service_id: default_service.id}, without_protection: true)
+      account.update!({default_service_id: default_service.id})
       default_service.reload
 
       ThreeScale::Core::Service.expects(:make_default).never
diff --git a/test/unit/user_test.rb b/test/unit/user_test.rb
index a67325d51d..0bfcfab3ad 100644
--- a/test/unit/user_test.rb
+++ b/test/unit/user_test.rb
@@ -8,15 +8,6 @@ class UserTest < ActiveSupport::TestCase
   subject { @user || FactoryBot.create(:user) }
 
   should belong_to :account
-  should allow_mass_assignment_of :username
-  should allow_mass_assignment_of :email
-  should allow_mass_assignment_of :first_name
-  should allow_mass_assignment_of :last_name
-  should allow_mass_assignment_of :password
-  should allow_mass_assignment_of :password_confirmation
-  should allow_mass_assignment_of :conditions
-  should allow_mass_assignment_of :service_conditions
-  should allow_mass_assignment_of :job_role
 
   setup do
     ActionMailer::Base.deliveries = []
diff --git a/test/workers/delete_object_hierarchy_worker_test.rb b/test/workers/delete_object_hierarchy_worker_test.rb
index aa9b1b847e..a0d054bc16 100644
--- a/test/workers/delete_object_hierarchy_worker_test.rb
+++ b/test/workers/delete_object_hierarchy_worker_test.rb
@@ -238,8 +238,8 @@ class DeletePlanTest < ActiveSupport::TestCase
 
     def perform_expectations
       DeleteObjectHierarchyWorker.stubs(:perform_later)
-      DeleteObjectHierarchyWorker.expects(:perform_later).with(Contract.new({ id: contract.id }, without_protection: true), anything, 'destroy')
-      DeleteObjectHierarchyWorker.expects(:perform_later).with(Plan.new({ id: customized_plan.id }, without_protection: true), anything, 'destroy')
+      DeleteObjectHierarchyWorker.expects(:perform_later).with(Contract.new(id: contract.id), anything, 'destroy')
+      DeleteObjectHierarchyWorker.expects(:perform_later).with(Plan.new(id: customized_plan.id), anything, 'destroy')
     end
 
     class AccountPlanTest < DeletePlanTest
@@ -555,7 +555,7 @@ class DeleteCompleteAccountTest < ActiveSupport::TestCase
         buyer.save!
         topic = FactoryBot.create(:topic, user: buyer.admin_user, forum: provider.forum)
         before_objects << topic
-        topic_subscription = UserTopic.create({user: buyer.admin_user, topic:}, {without_protection: true})
+        topic_subscription = UserTopic.create(user: buyer.admin_user, topic: topic)
 
         perform_enqueued_jobs(queue: "deletion") do
           DeleteObjectHierarchyWorker.delete_later buyer