diff --git a/spec/factories/roles.rb b/spec/factories/roles.rb
new file mode 100644
index 0000000..8903531
--- /dev/null
+++ b/spec/factories/roles.rb
@@ -0,0 +1,35 @@
+FactoryBot.define do
+  factory :role do
+    sequence(:key) { |n| "role_#{n}" }
+    sequence(:name) { |n| "Role #{n}" }
+
+    trait :administrator do
+      key { 'administrator' }
+      name { 'Administrator' }
+    end
+
+    trait :super_admin do
+      key { 'super_admin' }
+      name { 'Super Admin' }
+    end
+
+    trait :account_owner do
+      key { 'account_owner' }
+      name { 'Account Owner' }
+    end
+
+    trait :agent do
+      key { 'agent' }
+      name { 'Agent' }
+    end
+  end
+
+  factory :user_role do
+    association :user
+    association :role
+
+    trait :granted_by do
+      association :granted_by, factory: :user
+    end
+  end
+end
diff --git a/spec/mailers/administrator_notifications/base_mailer_spec.rb b/spec/mailers/administrator_notifications/base_mailer_spec.rb
new file mode 100644
index 0000000..a0c76b7
--- /dev/null
+++ b/spec/mailers/administrator_notifications/base_mailer_spec.rb
@@ -0,0 +1,69 @@
+RSpec.describe AdministratorNotifications::BaseMailer, type: :mailer do
+  describe '#admin_emails' do
+    let!(:admin_user) { create(:user, email: 'admin@example.com') }
+    let!(:super_admin_user) { create(:user, email: 'super_admin@example.com') }
+    let!(:agent_user) { create(:user, email: 'agent@example.com') }
+    let!(:admin_role) { create(:role, key: 'administrator') }
+    let!(:super_admin_role) { create(:role, key: 'super_admin') }
+    let!(:agent_role) { create(:role, key: 'agent') }
+
+    before do
+      admin_user.roles << admin_role
+      super_admin_user.roles << super_admin_role
+      agent_user.roles << agent_role
+    end
+
+    it 'returns emails of admin users' do
+      mailer_class = described_class.new
+      admin_emails = mailer_class.send(:admin_emails)
+
+      expect(admin_emails).to match_array(['admin@example.com', 'super_admin@example.com'])
+    end
+
+    it 'does not include agent users' do
+      mailer_class = described_class.new
+      admin_emails = mailer_class.send(:admin_emails)
+
+      expect(admin_emails).not_to include('agent@example.com')
+    end
+  end
+
+  describe '#send_notification' do
+    let!(:admin_user) { create(:user, email: 'admin@example.com') }
+    let!(:admin_role) { create(:role, key: 'administrator') }
+
+    before do
+      admin_user.roles << admin_role
+      allow(ENV).to receive(:fetch).with('FRONTEND_URL', nil).and_return('http://example.com')
+    end
+
+    it 'sends notification to admin emails' do
+      mail = described_class.send_notification(
+        'Test Subject',
+        action_url: 'http://example.com/action',
+        meta: { key: 'value' }
+      )
+
+      expect(mail.to).to include('admin@example.com')
+    end
+
+    it 'includes action URL in action_url variable' do
+      mail = described_class.send_notification(
+        'Test Subject',
+        action_url: 'http://example.com/action'
+      )
+
+      expect(mail.body.encoded).to include('http://example.com/action')
+    end
+
+    it 'includes meta data' do
+      mail = described_class.send_notification(
+        'Test Subject',
+        action_url: 'http://example.com/action',
+        meta: { key: 'value' }
+      )
+
+      expect(mail.body.encoded).to include('value')
+    end
+  end
+end
diff --git a/spec/migrations/20241020000100_optimize_contacts_performance_spec.rb b/spec/migrations/20241020000100_optimize_contacts_performance_spec.rb
new file mode 100644
index 0000000..3585e27
--- /dev/null
+++ b/spec/migrations/20241020000100_optimize_contacts_performance_spec.rb
@@ -0,0 +1,87 @@
+require 'rails_helper'
+require_relative '../../db/migrate/20241020000100_optimize_contacts_performance'
+
+RSpec.describe OptimizeContactsPerformance, type: :migration do
+  let(:migration) { described_class.new }
+
+  describe '#up' do
+    it 'creates idx_contact_inboxes_contact_id partial index' do
+      migration.up
+
+      expect(ActiveRecord::Base.connection.index_exists?(
+        :contact_inboxes,
+        :contact_id,
+        name: 'idx_contact_inboxes_contact_id',
+        where: 'contact_id IS NOT NULL'
+      )).to be true
+    end
+
+    it 'creates idx_contacts_with_identity partial index' do
+      migration.up
+
+      expect(ActiveRecord::Base.connection.index_exists?(
+        :contacts,
+        :id,
+        name: 'idx_contacts_with_identity',
+        where: "(email <> '' OR phone_number <> '' OR identifier <> '')"
+      )).to be true
+    end
+
+    context 'when contacts.type column does not exist' do
+      before do
+        # Ensure type column doesn't exist
+        ActiveRecord::Base.connection.remove_column(:contacts, :type) if ActiveRecord::Base.connection.column_exists?(:contacts, :type)
+      end
+
+      it 'skips creating idx_contacts_name_type_resolved without error' do
+        expect { migration.up }.not_to raise_error
+      end
+    end
+
+    context 'when contacts.type column exists' do
+      before do
+        # Add type column if it doesn't exist
+        unless ActiveRecord::Base.connection.column_exists?(:contacts, :type)
+          ActiveRecord::Base.connection.add_column(:contacts, :type, :string)
+        end
+      end
+
+      after do
+        ActiveRecord::Base.connection.remove_column(:contacts, :type) if ActiveRecord::Base.connection.column_exists?(:contacts, :type)
+      end
+
+      it 'creates idx_contacts_name_type_resolved composite index' do
+        migration.up
+
+        expect(ActiveRecord::Base.connection.index_exists?(
+          :contacts,
+          %i[name type id],
+          name: 'idx_contacts_name_type_resolved',
+          where: "(email <> '' OR phone_number <> '' OR identifier <> '')"
+        )).to be true
+      end
+    end
+  end
+
+  describe '#down' do
+    before do
+      migration.up
+    end
+
+    it 'removes all created indexes' do
+      migration.down
+
+      expect(ActiveRecord::Base.connection.index_exists?(
+        :contact_inboxes,
+        :contact_id,
+        name: 'idx_contact_inboxes_contact_id'
+      )).to be false
+
+      expect(ActiveRecord::Base.connection.index_exists?(
+        :contacts,
+        :id,
+        name: 'idx_contacts_with_identity'
+      )).to be false
+    end
+  end
+end
diff --git a/spec/migrations/20251117132621_add_type_to_contacts_spec.rb b/spec/migrations/20251117132621_add_type_to_contacts_spec.rb
new file mode 100644
index 0000000..4879986
--- /dev/null
+++ b/spec/migrations/20251117132621_add_type_to_contacts_spec.rb
@@ -0,0 +1,65 @@
+require 'rails_helper'
+require_relative '../../db/migrate/20251117132621_add_type_to_contacts'
+
+RSpec.describe AddTypeToContacts, type: :migration do
+  let(:migration) { described_class.new }
+
+  describe '#up' do
+    it 'adds type column to contacts' do
+      migration.up
+
+      expect(ActiveRecord::Base.connection.column_exists?(:contacts, :type)).to be true
+    end
+
+    it 'creates contact_type_enum type' do
+      migration.up
+
+      types = ActiveRecord::Base.connection.query('SELECT unnest(enum_range(NULL::contact_type_enum))')
+      expect(types.flatten).to match_array(['person', 'company'])
+    end
+
+    it 'sets default value to person' do
+      migration.up
+
+      column = ActiveRecord::Base.connection.columns(:contacts).find { |c| c.name == 'type' }
+      expect(column.default).to eq('person')
+    end
+
+    it 'creates index on type column' do
+      migration.up
+
+      expect(ActiveRecord::Base.connection.index_exists?(:contacts, :type)).to be true
+    end
+
+    it 'backfills idx_contacts_name_type_resolved index' do
+      migration.up
+
+      expect(ActiveRecord::Base.connection.index_exists?(
+        :contacts,
+        %i[name type id],
+        name: 'idx_contacts_name_type_resolved',
+        where: "(email <> '' OR phone_number <> '' OR identifier <> '')"
+      )).to be true
+    end
+  end
+
+  describe '#down' do
+    before do
+      migration.up
+    end
+
+    it 'removes type column' do
+      migration.down
+
+      expect(ActiveRecord::Base.connection.column_exists?(:contacts, :type)).to be false
+    end
+
+    it 'drops contact_type_enum type' do
+      migration.down
+
+      expect {
+        ActiveRecord::Base.connection.query('SELECT unnest(enum_range(NULL::contact_type_enum))')
+      }.to raise_error(ActiveRecord::StatementInvalid, /type "contact_type_enum" does not exist/)
+    end
+  end
+end
diff --git a/spec/models/role_spec.rb b/spec/models/role_spec.rb
new file mode 100644
index 0000000..0d32a2f
--- /dev/null
+++ b/spec/models/role_spec.rb
@@ -0,0 +1,80 @@
+RSpec.describe Role, type: :model do
+  describe 'associations' do
+    it { should have_many(:user_roles).dependent(:destroy_async) }
+    it { should have_many(:users).through(:user_roles) }
+  end
+
+  describe 'validations' do
+    it { should validate_presence_of(:key) }
+    it { should validate_presence_of(:name) }
+    it { should validate_uniqueness_of(:key) }
+  end
+
+  describe '.ADMIN_ROLE_KEYS' do
+    it 'includes super_admin, account_owner, administrator, admin' do
+      expect(Role::ADMIN_ROLE_KEYS).to match_array(%w[super_admin account_owner administrator admin])
+    end
+  end
+
+  describe '#administrator?' do
+    context 'when role key is in ADMIN_ROLE_KEYS' do
+      it 'returns true for super_admin' do
+        role = build(:role, key: 'super_admin')
+        expect(role.administrator?).to be true
+      end
+
+      it 'returns true for administrator' do
+        role = build(:role, key: 'administrator')
+        expect(role.administrator?).to be true
+      end
+
+      it 'returns true for account_owner' do
+        role = build(:role, key: 'account_owner')
+        expect(role.administrator?).to be true
+      end
+
+      it 'returns true for admin' do
+        role = build(:role, key: 'admin')
+        expect(role.administrator?).to be true
+      end
+    end
+
+    context 'when role key is not in ADMIN_ROLE_KEYS' do
+      it 'returns false for agent role' do
+        role = build(:role, key: 'agent')
+        expect(role.administrator?).to be false
+      end
+    end
+  end
+
+  describe '.administrator_role' do
+    let!(:admin_role) { create(:role, key: 'administrator') }
+    let!(:agent_role) { create(:role, key: 'agent') }
+
+    it 'returns first matching admin role' do
+      expect(Role.administrator_role).to eq(admin_role)
+    end
+  end
+
+  describe '.administrator_users' do
+    let!(:admin_role) { create(:role, key: 'administrator') }
+    let!(:super_admin_role) { create(:role, key: 'super_admin') }
+    let!(:admin_user) { create(:user) }
+    let!(:super_admin_user) { create(:user) }
+    let!(:agent_user) { create(:user) }
+
+    before do
+      admin_user.roles << admin_role
+      super_admin_user.roles << super_admin_role
+      agent_user.roles << create(:role, key: 'agent')
+    end
+
+    it 'returns all users with admin roles' do
+      expect(Role.administrator_users).to match_array([admin_user, super_admin_user])
+    end
+
+    it 'does not include agent users' do
+      expect(Role.administrator_users).not_to include(agent_user)
+    end
+  end
+end
diff --git a/spec/models/user_role_spec.rb b/spec/models/user_role_spec.rb
new file mode 100644
index 0000000..9f935a5
--- /dev/null
+++ b/spec/models/user_role_spec.rb
@@ -0,0 +1,14 @@
+RSpec.describe UserRole, type: :model do
+  describe 'associations' do
+    it { should belong_to(:user) }
+    it { should belong_to(:role) }
+    it { should belong_to(:granted_by).class_name('User').optional }
+  end
+
+  describe 'validations' do
+    subject { build(:user_role) }
+
+    it { should validate_presence_of(:user) }
+    it { should validate_presence_of(:role) }
+  end
+end