diff --git a/tools/internal_ci/helper_scripts/prepare_build_macos_rc b/tools/internal_ci/helper_scripts/prepare_build_macos_rc
index a13c29ea7f5..af6ba65cc19 100644
--- a/tools/internal_ci/helper_scripts/prepare_build_macos_rc
+++ b/tools/internal_ci/helper_scripts/prepare_build_macos_rc
@@ -18,6 +18,13 @@
 launchctl limit maxfiles
 ulimit -a
 
+# WARNING: TRY TO KEEP THIS FILE AS LEAN AS POSSIBLE
+# The rules:
+# - think twice before adding installer that takes long time (builds are already slow)
+# - do not add any steps that are flaky (builds will become flaky)
+# - try adding a dependency under a language-specific section first (reduces latency and increases build stability)
+# - only add stuff that you absolutely need for your builds to work (add comment to explain why its needed)
+
 # Add GCP credentials for BQ access
 pip install --user google-api-python-client oauth2client
 export GOOGLE_APPLICATION_CREDENTIALS=${KOKORO_GFILE_DIR}/GrpcTesting-d0eeee2db331.json
@@ -27,62 +34,85 @@ if [ -n "$KOKORO_GITHUB_PULL_REQUEST_NUMBER" ]; then
   export RUN_TESTS_FLAGS="--filter_pr_tests --base_branch origin/$KOKORO_GITHUB_PULL_REQUEST_TARGET_BRANCH $RUN_TESTS_FLAGS"
 fi
 
-set +ex  # rvm script is very verbose and exits with errorcode
-# Advice from https://github.com/Homebrew/homebrew-cask/issues/8629#issuecomment-68641176
-brew update && brew upgrade brew-cask && brew cleanup && brew cask cleanup
-rvm --debug requirements ruby-2.5.0
-source $HOME/.rvm/scripts/rvm
-set -e  # rvm commands are very verbose
-time rvm install 2.5.0
-rvm use 2.5.0 --default
-time gem install bundler -v 1.17.3 --no-ri --no-doc
-time gem install cocoapods --version 1.3.1 --no-ri --no-doc
-time gem install rake-compiler --no-ri --no-doc
-rvm osx-ssl-certs status all
-rvm osx-ssl-certs update all
-set -ex
-
-# cocoapods
-export LANG=en_US.UTF-8
-# pre-fetch cocoapods master repo's most recent commit only
-mkdir -p ~/.cocoapods/repos
-time git clone --depth 1 https://github.com/CocoaPods/Specs.git ~/.cocoapods/repos/master
-
-# python
-time pip install --user virtualenv
-time pip install --user --upgrade Mako six tox setuptools twisted pyyaml pyjwt cryptography requests
-export PYTHONPATH=/Library/Python/3.4/site-packages
-
-# Install Python 3.7 and Python 3.8
-time curl -O https://www.python.org/ftp/python/3.7.0/python-3.7.0-macosx10.9.pkg
-time curl -O https://www.python.org/ftp/python/3.8.0/python-3.8.0-macosx10.9.pkg
-echo "ae0717a02efea3b0eb34aadc680dc498 python-3.7.0-macosx10.9.pkg" > /tmp/python_installer_checksum.md5
-echo "f5f9ae9f416170c6355cab7256bb75b5 python-3.8.0-macosx10.9.pkg" >> /tmp/python_installer_checksum.md5
-md5sum -c /tmp/python_installer_checksum.md5
-time sudo installer -pkg ./python-3.7.0-macosx10.9.pkg -target /
-time sudo installer -pkg ./python-3.8.0-macosx10.9.pkg -target /
-
-# set xcode version for Obj-C tests
-sudo xcode-select -switch /Applications/Xcode_9.2.app/Contents/Developer/
-
-# Disable some unwanted dotnet options
-export NUGET_XMLDOC_MODE=skip
-export DOTNET_SKIP_FIRST_TIME_EXPERIENCE=true
-export DOTNET_CLI_TELEMETRY_OPTOUT=true
+if [ "${PREPARE_BUILD_INSTALL_DEPS_RUBY}" == "true" ]
+then
+  set +ex  # rvm script is very verbose and exits with errorcode
+  # Advice from https://github.com/Homebrew/homebrew-cask/issues/8629#issuecomment-68641176
+  brew update && brew upgrade brew-cask && brew cleanup && brew cask cleanup
+  rvm --debug requirements ruby-2.5.0
+  source $HOME/.rvm/scripts/rvm
+  set -e  # rvm commands are very verbose
+  time rvm install 2.5.0
+  rvm use 2.5.0 --default
+  time gem install bundler -v 1.17.3 --no-ri --no-doc
+  time gem install cocoapods --version 1.3.1 --no-ri --no-doc
+  time gem install rake-compiler --no-ri --no-doc
+  rvm osx-ssl-certs status all
+  rvm osx-ssl-certs update all
+  set -ex
+fi
 
-# TODO(jtattermusch): better debugging of clock skew, remove once not needed
-date
+if [ "${PREPARE_BUILD_INSTALL_DEPS_OBJC}" == "true" ]
+then
+  # cocoapods
+  export LANG=en_US.UTF-8
+  # pre-fetch cocoapods master repo's most recent commit only
+  mkdir -p ~/.cocoapods/repos
+  time git clone --depth 1 https://github.com/CocoaPods/Specs.git ~/.cocoapods/repos/master
 
-time git submodule update --init
+  # set xcode version for Obj-C tests
+  sudo xcode-select -switch /Applications/Xcode_9.2.app/Contents/Developer/
+
+  # Needed for ios-binary-size
+  time pip install --user pyyaml pyjwt cryptography requests
+
+  # Store intermediate build files of ObjC tests into /tmpfs
+  # TODO(jtattermusch): this has likely been done to avoid running
+  # out of disk space when running ios-binary-size tests, but
+  # it would be good to revisit.
+  mkdir /tmpfs/Build-ios-binary-size
+  ln -s /tmpfs/Build-ios-binary-size src/objective-c/examples/Sample/Build
+  mkdir -p /tmpfs/DerivedData
+  rm -rf ~/Library/Developer/Xcode/DerivedData
+  mkdir -p ~/Library/Developer/Xcode
+  ln -s /tmpfs/DerivedData ~/Library/Developer/Xcode/DerivedData
+fi
+
+if [ "${PREPARE_BUILD_INSTALL_DEPS_PYTHON}" == "true" ]
+then
+  # python
+  time pip install --user virtualenv
+  time pip install --user --upgrade Mako six tox setuptools twisted pyyaml pyjwt cryptography requests
+  export PYTHONPATH=/Library/Python/3.4/site-packages
 
-# Store intermediate build files of ObjC tests into /tmpfs
-mkdir /tmpfs/Build-ios-binary-size
-ln -s /tmpfs/Build-ios-binary-size src/objective-c/examples/Sample/Build
-mkdir -p /tmpfs/DerivedData
-rm -rf ~/Library/Developer/Xcode/DerivedData
-mkdir -p ~/Library/Developer/Xcode
-ln -s /tmpfs/DerivedData ~/Library/Developer/Xcode/DerivedData
+  # make sure md5sum is available (requires coreutils 8.31+)
+  brew upgrade coreutils
+
+  # Install Python 3.7 and Python 3.8
+  time curl -O https://www.python.org/ftp/python/3.7.0/python-3.7.0-macosx10.9.pkg
+  time curl -O https://www.python.org/ftp/python/3.8.0/python-3.8.0-macosx10.9.pkg
+  echo "ae0717a02efea3b0eb34aadc680dc498 python-3.7.0-macosx10.9.pkg" > /tmp/python_installer_checksum.md5
+  echo "f5f9ae9f416170c6355cab7256bb75b5 python-3.8.0-macosx10.9.pkg" >> /tmp/python_installer_checksum.md5
+  md5sum -c /tmp/python_installer_checksum.md5
+  time sudo installer -pkg ./python-3.7.0-macosx10.9.pkg -target /
+  time sudo installer -pkg ./python-3.8.0-macosx10.9.pkg -target /
+fi
+
+if [ "${PREPARE_BUILD_INSTALL_DEPS_CSHARP}" == "true" ]
+then
+  # Disable some unwanted dotnet options
+  export NUGET_XMLDOC_MODE=skip
+  export DOTNET_SKIP_FIRST_TIME_EXPERIENCE=true
+  export DOTNET_CLI_TELEMETRY_OPTOUT=true
+
+  # Xcode 10+ doesn't support building for i386 architecture
+  sudo xcode-select -switch /Applications/Xcode_9.2.app/Contents/Developer/
+fi
 
 # PHP tests currently require using an older version of PHPUnit
 ln -sf /usr/local/bin/phpunit-5.7 /usr/local/bin/phpunit
 
+# TODO(jtattermusch): better debugging of clock skew, remove once not needed
+date
+
+time git submodule update --init
diff --git a/tools/internal_ci/macos/grpc_basictests_cpp_ios.cfg b/tools/internal_ci/macos/grpc_basictests_cpp_ios.cfg
index 3c8e402d3fc..d3b81517da4 100644
--- a/tools/internal_ci/macos/grpc_basictests_cpp_ios.cfg
+++ b/tools/internal_ci/macos/grpc_basictests_cpp_ios.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 120
 action {
diff --git a/tools/internal_ci/macos/grpc_basictests_csharp.cfg b/tools/internal_ci/macos/grpc_basictests_csharp.cfg
index d3e04e71f71..6c48a5bcf1f 100644
--- a/tools/internal_ci/macos/grpc_basictests_csharp.cfg
+++ b/tools/internal_ci/macos/grpc_basictests_csharp.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_basictests_csharp.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 60
 action {
diff --git a/tools/internal_ci/macos/grpc_basictests_csharp.sh b/tools/internal_ci/macos/grpc_basictests_csharp.sh
new file mode 100755
index 00000000000..c66e5c7738f
--- /dev/null
+++ b/tools/internal_ci/macos/grpc_basictests_csharp.sh
@@ -0,0 +1,19 @@
+#!/bin/bash
+# Copyright 2019 The gRPC Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -ex
+
+export PREPARE_BUILD_INSTALL_DEPS_CSHARP=true
+$(dirname $0)/grpc_run_tests_matrix.sh
diff --git a/tools/internal_ci/macos/grpc_basictests_dbg.cfg b/tools/internal_ci/macos/grpc_basictests_dbg.cfg
deleted file mode 100644
index 1c7ed26d648..00000000000
--- a/tools/internal_ci/macos/grpc_basictests_dbg.cfg
+++ /dev/null
@@ -1,31 +0,0 @@
-# Copyright 2017 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# Config file for the internal CI (in protobuf text format)
-
-# Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
-gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
-timeout_mins: 240
-action {
-  define_artifacts {
-    regex: "**/*sponge_log.*"
-    regex: "github/grpc/reports/**"
-  }
-}
-
-env_vars {
-  key: "RUN_TESTS_FLAGS"
-  value: "-f basictests macos dbg --exclude objc --internal_ci -j 1 --inner_jobs 4 --bq_result_table aggregate_results"
-}
diff --git a/tools/internal_ci/macos/grpc_basictests_objc_examples.cfg b/tools/internal_ci/macos/grpc_basictests_objc_examples.cfg
index bdfd62c7937..309c4429d17 100644
--- a/tools/internal_ci/macos/grpc_basictests_objc_examples.cfg
+++ b/tools/internal_ci/macos/grpc_basictests_objc_examples.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 120
 action {
diff --git a/tools/internal_ci/macos/grpc_basictests_objc_ios.cfg b/tools/internal_ci/macos/grpc_basictests_objc_ios.cfg
index faef331cab5..dc9adbdc566 100644
--- a/tools/internal_ci/macos/grpc_basictests_objc_ios.cfg
+++ b/tools/internal_ci/macos/grpc_basictests_objc_ios.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 120
 action {
diff --git a/tools/internal_ci/macos/grpc_basictests_objc_mac.cfg b/tools/internal_ci/macos/grpc_basictests_objc_mac.cfg
index 19849c357f3..1087217217f 100644
--- a/tools/internal_ci/macos/grpc_basictests_objc_mac.cfg
+++ b/tools/internal_ci/macos/grpc_basictests_objc_mac.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 120
 action {
diff --git a/tools/internal_ci/macos/grpc_basictests_objc_tvos.cfg b/tools/internal_ci/macos/grpc_basictests_objc_tvos.cfg
index a3f3935b5d6..17940f48c36 100644
--- a/tools/internal_ci/macos/grpc_basictests_objc_tvos.cfg
+++ b/tools/internal_ci/macos/grpc_basictests_objc_tvos.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 120
 action {
diff --git a/tools/internal_ci/macos/grpc_basictests_opt.cfg b/tools/internal_ci/macos/grpc_basictests_opt.cfg
deleted file mode 100644
index f46ebaa7866..00000000000
--- a/tools/internal_ci/macos/grpc_basictests_opt.cfg
+++ /dev/null
@@ -1,31 +0,0 @@
-# Copyright 2017 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# Config file for the internal CI (in protobuf text format)
-
-# Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
-gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
-timeout_mins: 240
-action {
-  define_artifacts {
-    regex: "**/*sponge_log.*"
-    regex: "github/grpc/reports/**"
-  }
-}
-
-env_vars {
-  key: "RUN_TESTS_FLAGS"
-  value: "-f basictests macos opt --exclude objc --internal_ci -j 1 --inner_jobs 4 --bq_result_table aggregate_results"
-}
diff --git a/tools/internal_ci/macos/grpc_basictests_python.cfg b/tools/internal_ci/macos/grpc_basictests_python.cfg
index ae80ac317ff..77ae336803c 100644
--- a/tools/internal_ci/macos/grpc_basictests_python.cfg
+++ b/tools/internal_ci/macos/grpc_basictests_python.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_basictests_python.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 60
 action {
diff --git a/tools/internal_ci/macos/grpc_basictests_python.sh b/tools/internal_ci/macos/grpc_basictests_python.sh
new file mode 100755
index 00000000000..a0dabbd3c1e
--- /dev/null
+++ b/tools/internal_ci/macos/grpc_basictests_python.sh
@@ -0,0 +1,19 @@
+#!/bin/bash
+# Copyright 2019 The gRPC Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -ex
+
+export PREPARE_BUILD_INSTALL_DEPS_PYTHON=true
+$(dirname $0)/grpc_run_tests_matrix.sh
diff --git a/tools/internal_ci/macos/grpc_basictests_ruby.cfg b/tools/internal_ci/macos/grpc_basictests_ruby.cfg
index 3a28f97a54b..51b4d87e0a4 100644
--- a/tools/internal_ci/macos/grpc_basictests_ruby.cfg
+++ b/tools/internal_ci/macos/grpc_basictests_ruby.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_basictests_ruby.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 60
 action {
diff --git a/tools/internal_ci/macos/grpc_basictests_ruby.sh b/tools/internal_ci/macos/grpc_basictests_ruby.sh
new file mode 100755
index 00000000000..d83cd1e61c0
--- /dev/null
+++ b/tools/internal_ci/macos/grpc_basictests_ruby.sh
@@ -0,0 +1,19 @@
+#!/bin/bash
+# Copyright 2019 The gRPC Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -ex
+
+export PREPARE_BUILD_INSTALL_DEPS_RUBY=true
+$(dirname $0)/grpc_run_tests_matrix.sh
diff --git a/tools/internal_ci/macos/grpc_build_artifacts.sh b/tools/internal_ci/macos/grpc_build_artifacts.sh
index 4b450bf0c5a..10fe02a1215 100755
--- a/tools/internal_ci/macos/grpc_build_artifacts.sh
+++ b/tools/internal_ci/macos/grpc_build_artifacts.sh
@@ -18,6 +18,9 @@ set -ex
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
+export PREPARE_BUILD_INSTALL_DEPS_CSHARP=true
+export PREPARE_BUILD_INSTALL_DEPS_PYTHON=true
+export PREPARE_BUILD_INSTALL_DEPS_RUBY=true
 source tools/internal_ci/helper_scripts/prepare_build_macos_rc
 
 # install cython for all python versions
diff --git a/tools/internal_ci/macos/grpc_distribtests.sh b/tools/internal_ci/macos/grpc_distribtests.sh
index eb256d92ee8..ec51a51e56c 100644
--- a/tools/internal_ci/macos/grpc_distribtests.sh
+++ b/tools/internal_ci/macos/grpc_distribtests.sh
@@ -18,6 +18,7 @@ set -ex
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
+export PREPARE_BUILD_INSTALL_DEPS_CSHARP=true
 source tools/internal_ci/helper_scripts/prepare_build_macos_rc
 
 # Move packages generated by the previous step in the build chain.
diff --git a/tools/internal_ci/macos/grpc_ios_binary_size.sh b/tools/internal_ci/macos/grpc_ios_binary_size.sh
index 17937a30d41..523e3ae8b7d 100755
--- a/tools/internal_ci/macos/grpc_ios_binary_size.sh
+++ b/tools/internal_ci/macos/grpc_ios_binary_size.sh
@@ -21,6 +21,7 @@ set -ex
 # Enter the gRPC repo root
 cd $(dirname $0)/../../..
 
+export PREPARE_BUILD_INSTALL_DEPS_OBJC=true
 source tools/internal_ci/helper_scripts/prepare_build_macos_rc
 
 tools/profiling/ios_bin/binary_size.py \
diff --git a/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh b/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh
new file mode 100755
index 00000000000..72cd1954a48
--- /dev/null
+++ b/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh
@@ -0,0 +1,19 @@
+#!/bin/bash
+# Copyright 2019 The gRPC Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -ex
+
+export PREPARE_BUILD_INSTALL_DEPS_OBJC=true
+$(dirname $0)/grpc_run_tests_matrix.sh
diff --git a/tools/internal_ci/macos/pull_request/grpc_basictests_cpp_ios.cfg b/tools/internal_ci/macos/pull_request/grpc_basictests_cpp_ios.cfg
index f831aba3b94..a34b9aa9ff2 100644
--- a/tools/internal_ci/macos/pull_request/grpc_basictests_cpp_ios.cfg
+++ b/tools/internal_ci/macos/pull_request/grpc_basictests_cpp_ios.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 120
 action {
diff --git a/tools/internal_ci/macos/pull_request/grpc_basictests_csharp.cfg b/tools/internal_ci/macos/pull_request/grpc_basictests_csharp.cfg
index c9c1403693c..5ee22e375d0 100644
--- a/tools/internal_ci/macos/pull_request/grpc_basictests_csharp.cfg
+++ b/tools/internal_ci/macos/pull_request/grpc_basictests_csharp.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_basictests_csharp.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 60
 action {
diff --git a/tools/internal_ci/macos/pull_request/grpc_basictests_objc_examples.cfg b/tools/internal_ci/macos/pull_request/grpc_basictests_objc_examples.cfg
index e2e55777ad1..79b4fef0c0e 100644
--- a/tools/internal_ci/macos/pull_request/grpc_basictests_objc_examples.cfg
+++ b/tools/internal_ci/macos/pull_request/grpc_basictests_objc_examples.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 120
 action {
diff --git a/tools/internal_ci/macos/pull_request/grpc_basictests_objc_ios.cfg b/tools/internal_ci/macos/pull_request/grpc_basictests_objc_ios.cfg
index 4a4539b2353..530dc1d41b9 100644
--- a/tools/internal_ci/macos/pull_request/grpc_basictests_objc_ios.cfg
+++ b/tools/internal_ci/macos/pull_request/grpc_basictests_objc_ios.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 120
 action {
diff --git a/tools/internal_ci/macos/pull_request/grpc_basictests_objc_mac.cfg b/tools/internal_ci/macos/pull_request/grpc_basictests_objc_mac.cfg
index 98cf9345280..66f98d4d0d3 100644
--- a/tools/internal_ci/macos/pull_request/grpc_basictests_objc_mac.cfg
+++ b/tools/internal_ci/macos/pull_request/grpc_basictests_objc_mac.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 120
 action {
diff --git a/tools/internal_ci/macos/pull_request/grpc_basictests_objc_tvos.cfg b/tools/internal_ci/macos/pull_request/grpc_basictests_objc_tvos.cfg
index ec776def565..64d67ee53a9 100644
--- a/tools/internal_ci/macos/pull_request/grpc_basictests_objc_tvos.cfg
+++ b/tools/internal_ci/macos/pull_request/grpc_basictests_objc_tvos.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix_objc.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 120
 action {
diff --git a/tools/internal_ci/macos/pull_request/grpc_basictests_python.cfg b/tools/internal_ci/macos/pull_request/grpc_basictests_python.cfg
index c86871f80cb..4a084bf6a71 100644
--- a/tools/internal_ci/macos/pull_request/grpc_basictests_python.cfg
+++ b/tools/internal_ci/macos/pull_request/grpc_basictests_python.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_basictests_python.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 60
 action {
diff --git a/tools/internal_ci/macos/pull_request/grpc_basictests_ruby.cfg b/tools/internal_ci/macos/pull_request/grpc_basictests_ruby.cfg
index 5729bf8f751..1b60ddef9b0 100644
--- a/tools/internal_ci/macos/pull_request/grpc_basictests_ruby.cfg
+++ b/tools/internal_ci/macos/pull_request/grpc_basictests_ruby.cfg
@@ -15,7 +15,7 @@
 # Config file for the internal CI (in protobuf text format)
 
 # Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/macos/grpc_run_tests_matrix.sh"
+build_file: "grpc/tools/internal_ci/macos/grpc_basictests_ruby.sh"
 gfile_resources: "/bigstore/grpc-testing-secrets/gcp_credentials/GrpcTesting-d0eeee2db331.json"
 timeout_mins: 60
 action {