diff --git a/changelogs/unreleased/backfill-routes-for-users-migration.yml b/changelogs/unreleased/backfill-routes-for-users-migration.yml
new file mode 100644
index 0000000000000000000000000000000000000000..c883d95ca0d90c08066d5a85924174aa3c55e671
--- /dev/null
+++ b/changelogs/unreleased/backfill-routes-for-users-migration.yml
@@ -0,0 +1,5 @@
+---
+title: Backfill missing routes for Bot users
+merge_request: 35960
+author:
+type: fixed
diff --git a/db/post_migrate/20200703064117_generate_missing_routes_for_bots.rb b/db/post_migrate/20200703064117_generate_missing_routes_for_bots.rb
new file mode 100644
index 0000000000000000000000000000000000000000..85d62cbb6ddbe7abf65aab3f992e8e62cda48901
--- /dev/null
+++ b/db/post_migrate/20200703064117_generate_missing_routes_for_bots.rb
@@ -0,0 +1,92 @@
+# frozen_string_literal: true
+
+class GenerateMissingRoutesForBots < ActiveRecord::Migration[6.0]
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  class User < ActiveRecord::Base
+    self.table_name = 'users'
+
+    USER_TYPES = {
+      human: nil,
+      support_bot: 1,
+      alert_bot: 2,
+      visual_review_bot: 3,
+      service_user: 4,
+      ghost: 5,
+      project_bot: 6,
+      migration_bot: 7
+    }.with_indifferent_access.freeze
+
+    BOT_USER_TYPES = %w[alert_bot project_bot support_bot visual_review_bot migration_bot].freeze
+
+    scope :bots, -> { where(user_type: USER_TYPES.values_at(*BOT_USER_TYPES)) }
+  end
+
+  class Route < ActiveRecord::Base
+    self.table_name = 'routes'
+
+    validates :path,
+      uniqueness: { case_sensitive: false }
+  end
+
+  class Namespace < ActiveRecord::Base
+    self.table_name = 'namespaces'
+
+    belongs_to :owner, class_name: 'GenerateMissingRoutesForBots::User'
+
+    scope :for_user, -> { where('type IS NULL') }
+    scope :for_bots, -> { for_user.joins(:owner).merge(GenerateMissingRoutesForBots::User.bots) }
+
+    scope :without_routes, -> do
+      where(
+        'NOT EXISTS (
+          SELECT 1
+          FROM routes
+          WHERE source_type = ?
+          AND source_id = namespaces.id
+        )',
+          self.source_type_for_route
+      )
+    end
+
+    def self.source_type_for_route
+      'Namespace'
+    end
+
+    def attributes_for_insert
+      {
+        source_type: self.class.source_type_for_route,
+        source_id: id,
+        name: name,
+        path: path
+      }
+    end
+  end
+
+  def up
+    # Reset the column information of all the models that update the database
+    # to ensure the Active Record's knowledge of the table structure is current
+    Route.reset_column_information
+
+    logger = Gitlab::BackgroundMigration::Logger.build
+    attributes_to_be_logged = %w(id path name)
+
+    GenerateMissingRoutesForBots::Namespace.for_bots.without_routes.each do |namespace|
+      route = GenerateMissingRoutesForBots::Route.create(namespace.attributes_for_insert)
+      namespace_details = namespace.as_json.slice(*attributes_to_be_logged)
+
+      if route.persisted?
+        logger.info namespace_details.merge(message: 'a new route was created for the namespace')
+      else
+        errors = route.errors.full_messages.join(',')
+        logger.info namespace_details.merge(message: 'route creation failed for the namespace', errors: errors)
+      end
+    end
+  end
+
+  def down
+    # no op
+  end
+end
diff --git a/db/structure.sql b/db/structure.sql
index 03f5b95313e1e101d4bead737d053cb474299aca..2f9a661f0a0b00c929eb258210e861d7df016416 100644
--- a/db/structure.sql
+++ b/db/structure.sql
@@ -23636,6 +23636,7 @@ COPY "schema_migrations" (version) FROM STDIN;
 20200701093859
 20200701205710
 20200702123805
+20200703064117
 20200703121557
 20200703154822
 20200704143633
diff --git a/spec/migrations/generate_missing_routes_for_bots_spec.rb b/spec/migrations/generate_missing_routes_for_bots_spec.rb
new file mode 100644
index 0000000000000000000000000000000000000000..8af22042350750559510f512997ba59230c4279e
--- /dev/null
+++ b/spec/migrations/generate_missing_routes_for_bots_spec.rb
@@ -0,0 +1,80 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+require Rails.root.join('db', 'post_migrate', '20200703064117_generate_missing_routes_for_bots.rb')
+
+RSpec.describe GenerateMissingRoutesForBots, :migration do
+  let(:users) { table(:users) }
+  let(:namespaces) { table(:namespaces) }
+  let(:routes) { table(:routes) }
+
+  let(:visual_review_bot) do
+    users.create!(email: 'visual-review-bot@gitlab.com', name: 'GitLab Visual Review Bot', username: 'visual-review-bot', user_type: 3, projects_limit: 5)
+  end
+
+  let(:migration_bot) do
+    users.create!(email: 'migration-bot@gitlab.com', name: 'GitLab Migration Bot', username: 'migration-bot', user_type: 7, projects_limit: 5)
+  end
+
+  let!(:visual_review_bot_namespace) do
+    namespaces.create!(owner_id: visual_review_bot.id, name: visual_review_bot.name, path: visual_review_bot.username)
+  end
+
+  let!(:migration_bot_namespace) do
+    namespaces.create!(owner_id: migration_bot.id, name: migration_bot.name, path: migration_bot.username)
+  end
+
+  context 'for bot users without an existing route' do
+    it 'creates new routes' do
+      expect { migrate! }.to change { routes.count }.by(2)
+    end
+
+    it 'creates new routes with the same path and name as their namespace' do
+      migrate!
+
+      [visual_review_bot, migration_bot].each do |bot|
+        namespace = namespaces.find_by(owner_id: bot.id)
+        route = route_for(namespace: namespace)
+
+        expect(route.path).to eq(namespace.path)
+        expect(route.name).to eq(namespace.name)
+      end
+    end
+  end
+
+  it 'does not create routes for bot users with existing routes' do
+    create_route!(namespace: visual_review_bot_namespace)
+    create_route!(namespace: migration_bot_namespace)
+
+    expect { migrate! }.not_to change { routes.count }
+  end
+
+  it 'does not create routes for human users without an existing route' do
+    human_namespace = create_human_namespace!(name: 'GitLab Human', username: 'human')
+
+    expect { migrate! }.not_to change { route_for(namespace: human_namespace) }
+  end
+
+  it 'does not create route for a bot user with a missing route, if a human user with the same path already exists' do
+    human_namespace = create_human_namespace!(name: visual_review_bot.name, username: visual_review_bot.username)
+    create_route!(namespace: human_namespace)
+
+    expect { migrate! }.not_to change { route_for(namespace: visual_review_bot_namespace) }
+  end
+
+  private
+
+  def create_human_namespace!(name:, username:)
+    human = users.create!(email: 'human@gitlab.com', name: name, username: username, user_type: nil, projects_limit: 5)
+    namespaces.create!(owner_id: human.id, name: human.name, path: human.username)
+  end
+
+  def create_route!(namespace:)
+    routes.create!(path: namespace.path, name: namespace.name, source_id: namespace.id, source_type: 'Namespace')
+  end
+
+  def route_for(namespace:)
+    routes.find_by(source_type: 'Namespace', source_id: namespace.id)
+  end
+end