diff --git a/app/controllers/repp/v1/account_controller.rb b/app/controllers/repp/v1/account_controller.rb
index e412b784d..85d79fe68 100644
--- a/app/controllers/repp/v1/account_controller.rb
+++ b/app/controllers/repp/v1/account_controller.rb
@@ -1,6 +1,6 @@
 module Repp
   module V1
-    class AccountController < BaseController
+    class AccountController < BaseController # rubocop:disable Metrics/ClassLength
       load_and_authorize_resource
 
       api :get, '/repp/v1/account'
diff --git a/app/controllers/repp/v1/contacts_controller.rb b/app/controllers/repp/v1/contacts_controller.rb
index 01230c7fe..309a53a36 100644
--- a/app/controllers/repp/v1/contacts_controller.rb
+++ b/app/controllers/repp/v1/contacts_controller.rb
@@ -9,7 +9,7 @@ module Repp
       desc 'Get all existing contacts'
       def index
         authorize! :check, Epp::Contact
-        records = current_user.registrar.contacts.order(created_at: :desc)
+        records = current_user.registrar.contacts
 
         q = records.ransack(search_params)
         q.sorts = 'created_at desc' if q.sorts.empty?
@@ -19,8 +19,7 @@ module Repp
                                    .includes(:domain_contacts, :registrant_domains, :registrar)
 
         render_success(data: { contacts: serialized_contacts(limited_contacts),
-                               count: contacts.count,
-                               statuses: Contact::STATUSES,
+                               count: contacts.count, statuses: Contact::STATUSES,
                                ident_types: Contact::Ident.types })
       end
 
@@ -156,7 +155,7 @@ module Repp
       end
 
       def serialized_contacts(contacts)
-        return contacts.map {|c| c.code } unless index_params[:details] == 'true'
+        return contacts.map(&code) unless index_params[:details] == 'true'
 
         address_processing = Contact.address_processing?
         contacts.map do |c|
diff --git a/app/controllers/repp/v1/domains/renews_controller.rb b/app/controllers/repp/v1/domains/renews_controller.rb
index f963cd3a7..26365dffc 100644
--- a/app/controllers/repp/v1/domains/renews_controller.rb
+++ b/app/controllers/repp/v1/domains/renews_controller.rb
@@ -51,14 +51,11 @@ module Repp
 
         def select_renewable_domains
           @epp_errors ||= ActiveModel::Errors.new(self)
-
-          if bulk_renew_params[:domains].instance_of?(Array)
-            @domains = bulk_renew_domains
-            @epp_errors.add(:epp_errors, msg: 'Domains cannot be empty', code: '2005') if @domains.empty?
-          else
-            @epp_errors.add(:epp_errors, msg: 'Domains attribute must be an array', code: '2005')
+          @domains = bulk_renew_domains
+          if @domains.empty?
+            @epp_errors.add(:epp_errors, msg: 'Domains cannot be empty',
+                                         code: '2005')
           end
-
           return handle_errors if @epp_errors.any?
         end
 
@@ -77,14 +74,18 @@ module Repp
         def bulk_renew_domains
           @epp_errors ||= ActiveModel::Errors.new(self)
           domains = []
-          bulk_renew_params[:domains].each do |idn|
-            domain = Epp::Domain.find_by(name: idn)
-            domains << domain if domain
-            next if domain
+          if bulk_renew_params[:domains].instance_of?(Array)
+            bulk_renew_params[:domains].each do |idn|
+              domain = Epp::Domain.find_by(name: idn)
+              domains << domain if domain
+              next if domain
 
-            @epp_errors.add(:epp_errors,
-                            msg: "Object does not exist: #{idn}",
-                            code: '2304')
+              @epp_errors.add(:epp_errors,
+                              msg: "Object does not exist: #{idn}",
+                              code: '2304')
+            end
+          else
+            @epp_errors.add(:epp_errors, msg: 'Domains attribute must be an array', code: '2005')
           end
 
           domains
diff --git a/app/controllers/repp/v1/domains_controller.rb b/app/controllers/repp/v1/domains_controller.rb
index 37f735b69..00005e84d 100644
--- a/app/controllers/repp/v1/domains_controller.rb
+++ b/app/controllers/repp/v1/domains_controller.rb
@@ -30,7 +30,7 @@ module Repp
       api :GET, '/repp/v1/domains/:domain_name'
       desc 'Get a specific domain'
       def show
-        @domain = Epp::Domain.find_by_name(params[:id])
+        @domain = Epp::Domain.find_by(name: params[:id])
         authorize! :info, @domain
 
         sponsor = @domain.registrar == current_user.registrar
@@ -251,34 +251,33 @@ module Repp
         dup_params = domain_params.to_h.dup
         return dup_params unless dup_params[:contacts]
 
-        new_contact_params = dup_params[:contacts].map do |c|
-          c.to_h.symbolize_keys
-        end
+        modify_contact_params(dup_params)
+      end
 
-        old_contact_params = @domain.domain_contacts.map do |c|
-          { code: c.contact_code_cache, type: c.name.downcase }
+      def modify_contact_params(params)
+        new_contact_params = params[:contacts].map { |c| c.to_h.symbolize_keys }
+        old_contact_params = @domain.domain_contacts.includes(:contact).map do |c|
+          { code: c.contact.code, type: c.name.downcase }
         end
-        dup_params[:contacts] = (new_contact_params - old_contact_params).map { |c| c.merge(action: 'add') }
-        dup_params[:contacts].concat((old_contact_params - new_contact_params)
-                             .map { |c| c.merge(action: 'rem') })
-
-        dup_params
+        params[:contacts] = (new_contact_params - old_contact_params).map do |c|
+          c.merge(action: 'add')
+        end
+        params[:contacts].concat((old_contact_params - new_contact_params)
+                         .map { |c| c.merge(action: 'rem') })
+        params
       end
 
       def domain_params
-        params.require(:domain)
-              .permit(:name, :period, :period_unit, :registrar,
-                      :transfer_code, :reserved_pw, :legal_document,
-                      :registrant, legal_document: %i[body type],
-                                   registrant: [%i[code verified]],
-                                   dns_keys: [%i[id flags alg protocol public_key action]],
-                                   nameservers: [[:id, :hostname,
-                                                  :action, { ipv4: [], ipv6: [] }]],
-                                   contacts: [%i[code type action]],
-                                   nameservers_attributes: [[:hostname, { ipv4: [], ipv6: [] }]],
-                                   admin_contacts: [], tech_contacts: [],
-                                   dnskeys_attributes: [%i[flags alg protocol public_key]],
-                                   delete: [:verified])
+        params.require(:domain).permit(:name, :period, :period_unit, :registrar, :transfer_code,
+                                       :reserved_pw, :legal_document, :registrant,
+                                       legal_document: %i[body type], registrant: [%i[code verified]],
+                                       dns_keys: [%i[id flags alg protocol public_key action]],
+                                       nameservers: [[:id, :hostname, :action, { ipv4: [], ipv6: [] }]],
+                                       contacts: [%i[code type action]],
+                                       nameservers_attributes: [[:hostname, { ipv4: [], ipv6: [] }]],
+                                       admin_contacts: [], tech_contacts: [],
+                                       dnskeys_attributes: [%i[flags alg protocol public_key]],
+                                       delete: [:verified])
       end
     end
   end
diff --git a/app/controllers/repp/v1/invoices_controller.rb b/app/controllers/repp/v1/invoices_controller.rb
index c8c6676ec..34c04ff72 100644
--- a/app/controllers/repp/v1/invoices_controller.rb
+++ b/app/controllers/repp/v1/invoices_controller.rb
@@ -115,4 +115,4 @@ module Repp
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/controllers/repp/v1/registrar/auth_controller.rb b/app/controllers/repp/v1/registrar/auth_controller.rb
index 8fba9eefb..f91cc8637 100644
--- a/app/controllers/repp/v1/registrar/auth_controller.rb
+++ b/app/controllers/repp/v1/registrar/auth_controller.rb
@@ -46,4 +46,4 @@ module Repp
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/controllers/repp/v1/registrar/summary_controller.rb b/app/controllers/repp/v1/registrar/summary_controller.rb
index 15f7d0164..0885d822a 100644
--- a/app/controllers/repp/v1/registrar/summary_controller.rb
+++ b/app/controllers/repp/v1/registrar/summary_controller.rb
@@ -11,33 +11,60 @@ module Repp
           if can?(:manage, :poll)
             user_notifications = user.unread_notifications
             notification = user_notifications.order('created_at DESC').take
-            notifications_count = user_notifications.count
-            if notification&.attached_obj_type && notification&.attached_obj_id
-              begin
-                object = object_by_type(notification.attached_obj_type)
-                         .find(notification.attached_obj_id)
-              rescue => e
-                # the data model might be inconsistent; or ...
-                # this could happen if the registrar does not dequeue messages, and then the domain was deleted
-                # SELECT messages.id, domains.name, messages.body FROM messages LEFT OUTER
-                # JOIN domains ON attached_obj_id::INTEGER = domains.id
-                # WHERE attached_obj_type = 'Epp::Domain' AND name IS NULL;
-                message = 'orphan message, domain deleted, registrar should dequeue: '
-                Rails.logger.error message + e.to_s
-              end
-            end
           end
 
-          data = serialize_data(registrar: registrar,
-                                notification: notification,
-                                notifications_count: notifications_count,
-                                object: object)
+          render_success(data: serialize_data(registrar: registrar,
+                                              notification: notification,
+                                              notifications_count: user_notifications&.count,
+                                              object: notification_object(notification)))
+        end
 
-          render_success(data: data)
+        def serialized_domain_transfer(object)
+          {
+            name: object.domain_name, trStatus: object.status,
+            reID: object.new_registrar.code,
+            reDate: object.transfer_requested_at.try(:iso8601),
+            acID: object.old_registrar.code,
+            acDate: object.transferred_at.try(:iso8601) || object.wait_until.try(:iso8601),
+            exDate: object.domain_valid_to.iso8601
+          }
+        end
+
+        def serialized_contact_update_action(object)
+          {
+            contacts: object.to_non_available_contact_codes,
+            operation: object.operation,
+            opDate: object.created_at.utc.xmlschema,
+            svTrid: object.id,
+            who: object.user.username,
+            reason: 'Auto-update according to official data',
+          }
         end
 
         private
 
+        # rubocop:disable Style/RescueStandardError
+        def notification_object(notification)
+          return unless notification
+
+          return unless notification.attached_obj_type || notification.attached_obj_id
+
+          begin
+            object_by_type(notification.attached_obj_type)
+              .find(notification.attached_obj_id)
+          rescue => e
+            # the data model might be inconsistent; or ...
+            # this could happen if the registrar does not dequeue messages,
+            # and then the domain was deleted
+            # SELECT messages.id, domains.name, messages.body FROM messages LEFT OUTER
+            # JOIN domains ON attached_obj_id::INTEGER = domains.id
+            # WHERE attached_obj_type = 'Epp::Domain' AND name IS NULL;
+            message = 'orphan message, domain deleted, registrar should dequeue: '
+            Rails.logger.error message + e.to_s
+          end
+        end
+        # rubocop:enable Style/RescueStandardError
+
         def object_by_type(object_type)
           Object.const_get(object_type)
         rescue NameError
@@ -83,29 +110,9 @@ module Repp
         def serialized_object(object, obj_type)
           return unless object
 
-          case obj_type
-          when 'DomainTransfer'
-            {
-              name: object.domain_name,
-              trStatus: object.status,
-              reID: object.new_registrar.code,
-              reDate: object.transfer_requested_at.try(:iso8601),
-              acID: object.old_registrar.code,
-              acDate: object.transferred_at.try(:iso8601) || object.wait_until.try(:iso8601),
-              exDate: object.domain_valid_to.iso8601,
-            }
-          when 'ContactUpdateAction'
-            {
-              contacts: object.to_non_available_contact_codes,
-              operation: object.operation,
-              opDate: object.created_at.utc.xmlschema,
-              svTrid: object.id,
-              who: object.user.username,
-              reason: 'Auto-update according to official data',
-            }
-          end
+          try("serialized_#{obj_type.underscore}", object)
         end
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/models/admin_domain_contact.rb b/app/models/admin_domain_contact.rb
index 9003afb0f..99f0d02da 100644
--- a/app/models/admin_domain_contact.rb
+++ b/app/models/admin_domain_contact.rb
@@ -6,7 +6,7 @@ class AdminDomainContact < DomainContact
     skipped_domains = []
     admin_contacts = where(contact: current_contact)
 
-    admin_contacts.includes(:domain).each do |admin_contact|
+    admin_contacts.includes(:domain).find_each do |admin_contact|
       if admin_contact.domain.bulk_update_prohibited?
         skipped_domains << admin_contact.domain.name
         next
diff --git a/app/models/tech_domain_contact.rb b/app/models/tech_domain_contact.rb
index 30db6dec7..7c3d22bfd 100644
--- a/app/models/tech_domain_contact.rb
+++ b/app/models/tech_domain_contact.rb
@@ -5,7 +5,7 @@ class TechDomainContact < DomainContact
     skipped_domains = []
     tech_contacts = where(contact: current_contact)
 
-    tech_contacts.includes(:domain).each do |tech_contact|
+    tech_contacts.includes(:domain).find_each do |tech_contact|
       if irreplaceable?(tech_contact)
         skipped_domains << tech_contact.domain.name
         next
diff --git a/lib/serializers/repp/contact.rb b/lib/serializers/repp/contact.rb
index c36fa3258..11d5457ae 100644
--- a/lib/serializers/repp/contact.rb
+++ b/lib/serializers/repp/contact.rb
@@ -10,13 +10,15 @@ module Serializers
         @simplify = options[:simplify] || false
       end
 
+      # rubocop:disable Metrics/MethodLength
+      # rubocop:disable Metrics/AbcSize
       def to_json(obj = contact)
         return simple_object if @simplify
 
-        json = { id: obj.uuid, code: obj.code, name: obj.name, ident: ident,
-                 email: obj.email, phone: obj.phone, created_at: obj.created_at,
-                 auth_info: obj.auth_info, statuses: statuses,
-                 disclosed_attributes: obj.disclosed_attributes, registrar: registrar }
+        json = { id: obj.uuid, code: obj.code, name: obj.name, ident: ident, phone: obj.phone,
+                 created_at: obj.created_at, auth_info: obj.auth_info, email: obj.email,
+                 statuses: statuses, disclosed_attributes: obj.disclosed_attributes,
+                 registrar: registrar }
         json[:address] = address if @show_address
         if @domain_params
           json[:domains] = domains
@@ -24,6 +26,8 @@ module Serializers
         end
         json
       end
+      # rubocop:enable Metrics/MethodLength
+      # rubocop:enable Metrics/AbcSize
 
       def registrar
         contact.registrar.as_json(only: %i[name website])
diff --git a/lib/serializers/repp/domain.rb b/lib/serializers/repp/domain.rb
index 07bb95e36..cd0be8e25 100644
--- a/lib/serializers/repp/domain.rb
+++ b/lib/serializers/repp/domain.rb
@@ -9,6 +9,7 @@ module Serializers
         @simplify = simplify
       end
 
+      # rubocop:disable Metrics/MethodLength
       # rubocop:disable Metrics/AbcSize
       def to_json(obj = domain)
         return simple_object if @simplify
@@ -26,6 +27,7 @@ module Serializers
         json[:transfer_code] = obj.auth_info if @sponsored
         json
       end
+      # rubocop:enable Metrics/MethodLength
       # rubocop:enable Metrics/AbcSize
 
       def contacts
diff --git a/lib/serializers/repp/invoice.rb b/lib/serializers/repp/invoice.rb
index 9bc7431b2..f4ab4a1db 100644
--- a/lib/serializers/repp/invoice.rb
+++ b/lib/serializers/repp/invoice.rb
@@ -8,6 +8,8 @@ module Serializers
         @simplify = simplify
       end
 
+      # rubocop:disable Metrics/MethodLength
+      # rubocop:disable Metrics/AbcSize
       def to_json(obj = invoice)
         return simple_object if @simplify
 
@@ -29,16 +31,11 @@ module Serializers
 
       def seller
         {
-          name: invoice.seller_name,
-          reg_no: invoice.seller_reg_no,
-          iban: invoice.seller_iban,
-          bank: invoice.seller_bank,
-          swift: invoice.seller_swift,
-          vat_no: invoice.seller_vat_no,
-          address: invoice.seller_address,
-          country: invoice.seller_country.name,
-          phone: invoice.seller_phone,
-          url: invoice.seller_url,
+          name: invoice.seller_name, reg_no: invoice.seller_reg_no,
+          iban: invoice.seller_iban, bank: invoice.seller_bank,
+          swift: invoice.seller_swift, vat_no: invoice.seller_vat_no,
+          address: invoice.seller_address, country: invoice.seller_country.name,
+          phone: invoice.seller_phone, url: invoice.seller_url,
           email: invoice.seller_email,
           contact_name: invoice.seller_contact_name,
         }
@@ -80,6 +77,8 @@ module Serializers
           recipient: invoice.buyer.billing_email,
         }
       end
+      # rubocop:enable Metrics/MethodLength
+      # rubocop:enable Metrics/AbcSize
     end
   end
 end