diff --git a/.github/workflows/unit_tests.yml b/.github/workflows/unit_tests.yml
index f7780a9db85..640aa85bb19 100644
--- a/.github/workflows/unit_tests.yml
+++ b/.github/workflows/unit_tests.yml
@@ -80,8 +80,31 @@ jobs:
         restore-keys: |
           parallel-runtime-postgres-${{ matrix.image }}-
           parallel-runtime-postgres-
+    - name: Clear previous coverage
+      if: matrix.image == 'postgres:17'
+      run: rm -rf coverage
     - name: Run tests
+      env:
+        COVERAGE: ${{ matrix.image == 'postgres:17' && 'true' || '' }}
       run: DB=postgres POSTGRES_CONNECTION_PREFIX="postgres://postgres:rootpassword@localhost:5432" RSPEC_PROFILE="${{ inputs.rspec_profile }}" bundle exec rake spec
+    - name: Report coverage
+      if: matrix.image == 'postgres:17'
+      run: |
+        pct=$(ruby -rjson -e 'puts JSON.parse(File.read("coverage/coverage.json"))["total"]["lines"]["percent"].round(2)')
+        echo "Total line coverage: ${pct}%"
+        echo "## Test coverage: ${pct}%" >> "$GITHUB_STEP_SUMMARY"
+    - name: Upload coverage report
+      if: matrix.image == 'postgres:17'
+      uses: actions/upload-artifact@v7
+      with:
+        name: coverage-report
+        path: |
+          coverage/*.html
+          coverage/*.css
+          coverage/*.js
+          coverage/*.png
+          coverage/coverage.json
+        retention-days: 7
     - name: Save parallel_rspec runtime logs
       if: always() && github.ref == 'refs/heads/main'
       uses: actions/cache/save@v6
diff --git a/.simplecov b/.simplecov
new file mode 100644
index 00000000000..3a423823017
--- /dev/null
+++ b/.simplecov
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+# Namespaced command_name + long merge_timeout so spec:all's three invocations merge, not overwrite.
+SimpleCov.configure do
+  skip '/spec/'
+  skip '/errors/'
+  skip '/docs/'
+
+  merging true
+  merge_timeout 3600
+
+  suite = ENV.fetch('COVERAGE_SUITE', 'default')
+  worker = ENV['TEST_ENV_NUMBER'].to_s
+  worker = '1' if worker.empty?
+  command_name "#{suite}-#{worker}"
+end
diff --git a/Gemfile b/Gemfile
index a3151c8186f..ae74c619809 100644
--- a/Gemfile
+++ b/Gemfile
@@ -51,7 +51,6 @@ group :operations do
 end
 
 group :test do
-  gem 'codeclimate-test-reporter', '>= 1.0.8', require: false
   gem 'factory_bot', '~> 6.5'
   gem 'mock_redis'
   gem 'parallel_tests'
@@ -70,6 +69,7 @@ group :test do
   gem 'rubocop-rspec', '~> 3.10'
   gem 'rubocop-rspec_rails'
   gem 'rubocop-sequel', '~> 0.4.1'
+  gem 'simplecov', '~> 1.0', require: false
   gem 'timecop'
   gem 'webmock', '> 2.3.1'
   gem 'webrick', '~> 1.9.2'
diff --git a/Gemfile.lock b/Gemfile.lock
index 8a5ac3ecb21..90e89da2f8a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -54,8 +54,6 @@ GEM
     clockwork (4.0.1)
       activesupport
       tzinfo
-    codeclimate-test-reporter (1.0.9)
-      simplecov (<= 0.13)
     coderay (1.1.3)
     commander (5.0.0)
       highline (~> 3.0.0)
@@ -75,7 +73,6 @@ GEM
       logger
     diff-lcs (1.6.2)
     digest-xxhash (0.2.9)
-    docile (1.1.5)
     drb (2.2.3)
     erb (6.0.6)
     erubi (1.13.1)
@@ -356,11 +353,7 @@ GEM
       pg (>= 0.18.0, != 1.2.0)
       sequel (>= 4.38.0)
     sexp_processor (4.17.5)
-    simplecov (0.13.0)
-      docile (~> 1.1.0)
-      json (>= 1.8, < 3)
-      simplecov-html (~> 0.10.0)
-    simplecov-html (0.10.2)
+    simplecov (1.0.3)
     sinatra (4.2.1)
       logger (>= 1.6.0)
       mustermann (~> 3.0)
@@ -453,7 +446,6 @@ DEPENDENCIES
   byebug
   cf-uaa-lib (~> 4.0.10)
   clockwork
-  codeclimate-test-reporter (>= 1.0.8)
   concurrent-ruby
   debug (~> 1.11)
   digest-xxhash
@@ -503,6 +495,7 @@ DEPENDENCIES
   rubyzip (>= 1.3.0)
   sequel (~> 5.106)
   sequel_pg
+  simplecov (~> 1.0)
   sinatra (~> 4.2)
   sinatra-contrib
   solargraph
diff --git a/README.md b/README.md
index ca64ba13876..b4a8c4e0ce7 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,4 @@
-[![Code Climate](https://api.codeclimate.com/v1/badges/aa47fb93c59ced5fcc4f/maintainability)](https://codeclimate.com/github/cloudfoundry/cloud_controller_ng)
-[![Code Climate](https://api.codeclimate.com/v1/badges/aa47fb93c59ced5fcc4f/test_coverage)](https://codeclimate.com/github/cloudfoundry/cloud_controller_ng)
+[![Maintainability](https://qlty.sh/gh/cloudfoundry/projects/cloud_controller_ng/maintainability.svg)](https://qlty.sh/gh/cloudfoundry/projects/cloud_controller_ng)
 [![slack.cloudfoundry.org](https://slack.cloudfoundry.org/badge.svg)](https://cloudfoundry.slack.com/messages/capi/)
 
 # Welcome to the Cloud Controller
diff --git a/lib/tasks/spec.rake b/lib/tasks/spec.rake
index f8ea26c9e89..d11a9fae89d 100644
--- a/lib/tasks/spec.rake
+++ b/lib/tasks/spec.rake
@@ -4,11 +4,11 @@ task spec: 'spec:all'
 namespace :spec do
   task all: ['db:pick', 'db:parallel:recreate'] do
     if ARGV[1]
-      run_specs(ARGV[1])
+      run_specs(ARGV[1], coverage_env('adhoc'))
     else
-      run_specs_parallel('spec')
-      run_migration_specs_parallel
-      run_specs('spec/isolated_specs')
+      run_specs_parallel('spec', coverage_env('main'))
+      run_migration_specs_parallel(coverage_env('migrations'))
+      run_specs('spec/isolated_specs', coverage_env('isolated'))
     end
   end
 
@@ -70,6 +70,13 @@ namespace :spec do
     ENV['RSPEC_PROFILE'].to_s.empty? ? '' : "--profile #{ENV.fetch('RSPEC_PROFILE', nil)}"
   end
 
+  # Guard is required: ENV['COVERAGE'] == '' is truthy in Ruby.
+  def coverage_env(suite)
+    return '' unless ENV['COVERAGE'] && !ENV['COVERAGE'].empty?
+
+    "COVERAGE=true COVERAGE_SUITE=#{suite} "
+  end
+
   def run_failed_specs
     sh 'bundle exec rspec --only-failures --color --tty spec --require rspec/instafail --format RSpec::Instafail'
   end
diff --git a/spec/spec_helper_helper.rb b/spec/spec_helper_helper.rb
index e573a68c01c..99aa7e9dd81 100644
--- a/spec/spec_helper_helper.rb
+++ b/spec/spec_helper_helper.rb
@@ -10,11 +10,7 @@ def self.init
 
     if ENV['COVERAGE']
       require 'simplecov'
-      SimpleCov.start do
-        add_filter '/spec/'
-        add_filter '/errors/'
-        add_filter '/docs/'
-      end
+      SimpleCov.start
     end
     ENV['PB_IGNORE_DEPRECATIONS'] = 'true'
     ENV['RAILS_ENV'] ||= 'test'
@@ -98,7 +94,7 @@ def self.each_run
       rspec_config.include SpaceRestrictedResponseGenerators
 
       rspec_config.before(:all) do
-        WebMock.disable_net_connect!(allow: %w[codeclimate.com fake.bbs])
+        WebMock.disable_net_connect!(allow: %w[fake.bbs])
       end
       rspec_config.before(:all, type: :integration) do
         WebMock.allow_net_connect!
@@ -109,7 +105,7 @@ def self.each_run
         skip 'Skipped due to NO_DB_MIGRATION env variable being set' if ENV['NO_DB_MIGRATION']
       end
       rspec_config.after(:all, type: :integration) do
-        WebMock.disable_net_connect!(allow: %w[codeclimate.com fake.bbs])
+        WebMock.disable_net_connect!(allow: %w[fake.bbs])
         @uaa_server.stop
       end