diff --git a/tools/internal_ci/helper_scripts/delete_nonartifacts.sh b/tools/internal_ci/helper_scripts/delete_nonartifacts.sh
deleted file mode 100755
index 01e9427e1c7..00000000000
--- a/tools/internal_ci/helper_scripts/delete_nonartifacts.sh
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/usr/bin/env bash
-# Copyright 2018 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
-
-# change to grpc repo root
-cd "$(dirname "$0")/../../.."
-
-# After kokoro build finishes, the workspace gets rsync'ed to another machine,
-# from where the artifacts and reports are processed.
-# Especially on Windows, the rsync can take long time, so we cleanup the workspace
-# after finishing each build. We only leave files we want to keep:
-# - reports and artifacts
-# - directory containing the kokoro scripts to prevent deleting a script while being executed.
-time find . -type f -not -iname "*sponge_log.*" -not -path "./reports/*" -not -path "./artifacts/*" -not -path "./tools/internal_ci/*" -exec rm -f {} +
diff --git a/tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself.bat b/tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself.bat
new file mode 100644
index 00000000000..cdceeeee44d
--- /dev/null
+++ b/tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself.bat
@@ -0,0 +1,58 @@
+@rem Copyright 2021 The gRPC Authors
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem     http://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+
+@rem Call this script at the beginning of your CI script to move
+@rem the entire source tree to a different directory.
+@rem That avoids slow finalization (and a number of other problems)
+@rem caused by kokoro rsyncing the entire /tmpfs/src directory
+@rem back to the agent.
+@rem Since batch scripts don't support the "source" unix command,
+@rem invoking this script is a bit trickier than on unix.
+@rem This script should be invoked from the CI script like this:
+@rem IF "%cd%"=="T:\src" (
+@rem   call %~dp0\..\..\..\tools\internal_ci\helper_scripts\move_src_tree_and_respawn_itself.bat %0
+@rem   exit /b %errorlevel%
+@rem )
+
+@echo off
+
+@rem CI script path needs to be passed as arg1.
+set CI_SCRIPT_RELATIVE_TO_SRC=%1
+
+@rem Check that this script was invoked under correct circumstances.
+IF NOT "%cd%"=="T:\src" (
+  @echo "Error: Current directory must be T:\src when invoking move_src_tree_and_respawn_itself.bat"
+  exit /b 1
+)
+
+@rem T:\ is equivalent to /tmpfs on kokoro linux.
+echo "Moving workspace from T:\src to T:\altsrc and respawning the CI script."
+cd /d T:\
+@rem We cannot simply rename "src" to "altsrc" as on linux since the currently running batch file is in it
+@rem and windows holds a lock that prevents moving the dir.
+bash -c "set -ex; mkdir -p altsrc; time cp -r src/github altsrc;"
+@rem Delete files we can under the original "src/github" directory, skipping the directory that contains CI scripts
+@rem (as on of the scripts is currently running and cannot be deleted)
+@rem We don't want to delete files in "src" outside of "src/github" since they contain e.g kokoro input artifacts.
+bash -c "set -ex; cd src/github; time find . -type f -not -path './grpc/tools/internal_ci/*' -exec rm -f {} +; ls grpc"
+cd altsrc
+
+@rem scripts in tools/run_tests generate test reports and we need to make sure these reports
+@rem land in a directory that is going to be rsynced back to the kokoro agent.
+set GRPC_TEST_REPORT_BASE_DIR=T:\src\github\grpc
+
+echo "Invoking original CI script now."
+@echo on
+call "%CI_SCRIPT_RELATIVE_TO_SRC%"
+exit /b %errorlevel%
diff --git a/tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc b/tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
new file mode 100644
index 00000000000..ad915d68e24
--- /dev/null
+++ b/tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
@@ -0,0 +1,52 @@
+#!/bin/bash
+# Copyright 2021 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.
+
+# Source this rc script at the beginning of your CI script to move
+# the entire source tree to a different directory.
+# That avoids slow finalization (and a number of other problems)
+# caused by kokoro rsyncing the entire /tmpfs/src directory
+# back to the agent.
+# See b/74837748 for more context.
+
+set -ex
+
+CURRENT_DIR="$(pwd)"
+CI_SCRIPT_RELATIVE_TO_SRC="$0"
+
+if [ "${CURRENT_DIR}" == "/tmpfs/altsrc" ]
+then
+  # we already respawned under /tmpfs/altsrc, no need to do anything
+  echo "Successfully respawned the CI script ${CI_SCRIPT_RELATIVE_TO_SRC} under ${CURRENT_DIR}."
+  # scripts in tools/run_tests generate test reports and we need to make sure these reports
+  # land in a directory that is going to be rsynced back to the kokoro agent.
+  export GRPC_TEST_REPORT_BASE_DIR="/tmpfs/src/github/grpc"
+elif [ "${CURRENT_DIR}" == "/tmpfs/src" ]
+then
+  # we need to respawn now
+  # - step out of current directory
+  # - rename src/github to altsrc/github (/tmpfs/src is the directory that gets rsynced back to kokoro agent once the CI script finishes).
+  #   Note that we don't want to move the entire /tmpfs/src tree (which contains e.g. the input artifacts as well,
+  #   and their path is referenced by kokoro env variables), just /tmpfs/src/github
+  #   which contains all the cloned github repositories (=our workspace in which the build happens)
+  echo "Moving workspace from /tmpfs/src to /tmpfs/altsrc and respawning the CI script."
+  # once "exec bash" starts, the CI script in the original location will no longer be in use and it will be safe to move
+  # the entire "/tmpfs/src/github" tree (moving the bash script file while running is probably safe anyway on unix, but it doesn't
+  # hurt to be extra careful)
+  exec bash -c "set -ex; cd /tmpfs; mkdir -p altsrc; mv src/github altsrc; cd altsrc; exec '${CI_SCRIPT_RELATIVE_TO_SRC}'"
+else
+  # avoid messing with the workspace if we don't see the directory layout
+  # that's standard on kokoro (in case this script gets accidentally invoked outside of kokoro)
+  echo "Looks the script is currently not running on kokoro, skipping respawn and continuing the original CI script."
+fi
diff --git a/tools/internal_ci/helper_scripts/store_artifacts_from_moved_src_tree.sh b/tools/internal_ci/helper_scripts/store_artifacts_from_moved_src_tree.sh
new file mode 100755
index 00000000000..858e3cbc6c5
--- /dev/null
+++ b/tools/internal_ci/helper_scripts/store_artifacts_from_moved_src_tree.sh
@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+# Copyright 2021 The gRPC Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# If you have used "move_src_tree_and_respawn_itself_rc" in a CI script
+# and the script produces artifacts to be stored by kokoro, run this
+# at the end of the script.
+
+set -ex
+
+if [ "${GRPC_TEST_REPORT_BASE_DIR}" == "" ]
+then
+  # looks like the move_src_tree_and_respawn_itself_rc hasn't been used
+  # and we're not running under a moved source tree
+  exit 0
+fi
+
+# change to grpc repo root
+cd "$(dirname "$0")/../../.."
+
+# If running under a moved source tree (see grpc/tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc),
+# we need to copy the artifacts produced by the build to a location that's stored by kokoro.
+
+# artifacts in this directory will be stored by kokoro
+mkdir -p "${GRPC_TEST_REPORT_BASE_DIR}/artifacts"
+time cp -r artifacts/* "${GRPC_TEST_REPORT_BASE_DIR}/artifacts" || true
diff --git a/tools/internal_ci/linux/grpc_bazel_distribtest.cfg b/tools/internal_ci/linux/grpc_bazel_distribtest.cfg
index 00b398ddf5f..84a2ab35017 100644
--- a/tools/internal_ci/linux/grpc_bazel_distribtest.cfg
+++ b/tools/internal_ci/linux/grpc_bazel_distribtest.cfg
@@ -21,6 +21,5 @@ action {
   define_artifacts {
     regex: "**/*sponge_log.*"
     regex: "github/grpc/reports/**"
-    regex: "github/grpc/artifacts/**"
   }
 }
diff --git a/tools/internal_ci/linux/grpc_bazel_distribtest_latest.cfg b/tools/internal_ci/linux/grpc_bazel_distribtest_latest.cfg
index f0fe33c9459..04b51a8f7c6 100644
--- a/tools/internal_ci/linux/grpc_bazel_distribtest_latest.cfg
+++ b/tools/internal_ci/linux/grpc_bazel_distribtest_latest.cfg
@@ -21,6 +21,5 @@ action {
   define_artifacts {
     regex: "**/*sponge_log.*"
     regex: "github/grpc/reports/**"
-    regex: "github/grpc/artifacts/**"
   }
 }
diff --git a/tools/internal_ci/linux/grpc_build_artifacts.sh b/tools/internal_ci/linux/grpc_build_artifacts.sh
index 9cf6b2428de..0810790c37b 100755
--- a/tools/internal_ci/linux/grpc_build_artifacts.sh
+++ b/tools/internal_ci/linux/grpc_build_artifacts.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
@@ -26,4 +29,11 @@ set -e  # rvm commands are very verbose
 rvm --default use ruby-2.4.1
 set -ex
 
-tools/run_tests/task_runner.py -f artifact linux -j 12
+tools/run_tests/task_runner.py -f artifact linux -j 12 || FAILED="true"
+
+tools/internal_ci/helper_scripts/store_artifacts_from_moved_src_tree.sh
+
+if [ "$FAILED" != "" ]
+then
+  exit 1
+fi
diff --git a/tools/internal_ci/linux/grpc_build_packages.sh b/tools/internal_ci/linux/grpc_build_packages.sh
index ff71298add4..f9b8953ecf0 100644
--- a/tools/internal_ci/linux/grpc_build_packages.sh
+++ b/tools/internal_ci/linux/grpc_build_packages.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
@@ -33,4 +36,12 @@ mv ${KOKORO_GFILE_DIR}/github/grpc/artifacts input_artifacts || true
 chmod +x input_artifacts/protoc*/* || true
 ls -R input_artifacts || true
 
-tools/run_tests/task_runner.py -f package linux -j 6
+tools/run_tests/task_runner.py -f package linux -j 6 || FAILED="true"
+
+tools/internal_ci/helper_scripts/store_artifacts_from_moved_src_tree.sh
+
+if [ "$FAILED" != "" ]
+then
+  exit 1
+fi
+
diff --git a/tools/internal_ci/linux/grpc_distribtests.sh b/tools/internal_ci/linux/grpc_distribtests.sh
index 8a8111d557a..c809f22ee76 100644
--- a/tools/internal_ci/linux/grpc_distribtests.sh
+++ b/tools/internal_ci/linux/grpc_distribtests.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
diff --git a/tools/internal_ci/linux/grpc_distribtests_php.sh b/tools/internal_ci/linux/grpc_distribtests_php.sh
index a0de6701d43..aad8d65b9bb 100755
--- a/tools/internal_ci/linux/grpc_distribtests_php.sh
+++ b/tools/internal_ci/linux/grpc_distribtests_php.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
@@ -45,6 +48,8 @@ cp -r artifacts/* input_artifacts/ || true
 # a better signal about which distribtest are affected by the currently broken artifact builds.
 tools/run_tests/task_runner.py -f distribtest linux php -j 4 -x distribtests/sponge_log.xml || FAILED="true"
 
+tools/internal_ci/helper_scripts/store_artifacts_from_moved_src_tree.sh
+
 if [ "$FAILED" != "" ]
 then
   exit 1
diff --git a/tools/internal_ci/linux/grpc_distribtests_python.sh b/tools/internal_ci/linux/grpc_distribtests_python.sh
index 37f026d9674..a03309231d5 100755
--- a/tools/internal_ci/linux/grpc_distribtests_python.sh
+++ b/tools/internal_ci/linux/grpc_distribtests_python.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
@@ -50,6 +53,8 @@ cp -r artifacts/* input_artifacts/ || true
 # a better signal about which distribtest are affected by the currently broken artifact builds.
 tools/run_tests/task_runner.py -f distribtest linux python -j 12 -x distribtests/sponge_log.xml || FAILED="true"
 
+tools/internal_ci/helper_scripts/store_artifacts_from_moved_src_tree.sh
+
 if [ "$FAILED" != "" ]
 then
   exit 1
diff --git a/tools/internal_ci/linux/grpc_distribtests_ruby.sh b/tools/internal_ci/linux/grpc_distribtests_ruby.sh
index bb794e7f3b2..3da15534b8a 100755
--- a/tools/internal_ci/linux/grpc_distribtests_ruby.sh
+++ b/tools/internal_ci/linux/grpc_distribtests_ruby.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
@@ -46,6 +49,8 @@ cp -r artifacts/ruby_native_gem_*/* input_artifacts/ || true
 # a better signal about which distribtest are affected by the currently broken artifact builds.
 tools/run_tests/task_runner.py -f distribtest linux ruby -j 6 -x distribtests/sponge_log.xml || FAILED="true"
 
+tools/internal_ci/helper_scripts/store_artifacts_from_moved_src_tree.sh
+
 if [ "$FAILED" != "" ]
 then
   exit 1
diff --git a/tools/internal_ci/linux/grpc_distribtests_standalone.sh b/tools/internal_ci/linux/grpc_distribtests_standalone.sh
index 084daa9bc6a..f71f3b13773 100755
--- a/tools/internal_ci/linux/grpc_distribtests_standalone.sh
+++ b/tools/internal_ci/linux/grpc_distribtests_standalone.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
diff --git a/tools/internal_ci/linux/grpc_run_interop_tests.sh b/tools/internal_ci/linux/grpc_run_interop_tests.sh
index 1f4eda2d529..8b02bd05cff 100755
--- a/tools/internal_ci/linux/grpc_run_interop_tests.sh
+++ b/tools/internal_ci/linux/grpc_run_interop_tests.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 export LANG=en_US.UTF-8
 
 # Enter the gRPC repo root
diff --git a/tools/internal_ci/linux/grpc_run_tests_matrix.sh b/tools/internal_ci/linux/grpc_run_tests_matrix.sh
index 7c5b07a78c1..8f5d4f2f527 100755
--- a/tools/internal_ci/linux/grpc_run_tests_matrix.sh
+++ b/tools/internal_ci/linux/grpc_run_tests_matrix.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
diff --git a/tools/internal_ci/macos/grpc_build_artifacts.sh b/tools/internal_ci/macos/grpc_build_artifacts.sh
index 02b2331f5f1..2e4522a6f91 100755
--- a/tools/internal_ci/macos/grpc_build_artifacts.sh
+++ b/tools/internal_ci/macos/grpc_build_artifacts.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
@@ -40,7 +43,7 @@ update_rubygems
 
 tools/run_tests/task_runner.py -f artifact macos || FAILED="true"
 
-tools/internal_ci/helper_scripts/delete_nonartifacts.sh || true
+tools/internal_ci/helper_scripts/store_artifacts_from_moved_src_tree.sh
 
 if [ "$FAILED" != "" ]
 then
diff --git a/tools/internal_ci/macos/grpc_distribtests.sh b/tools/internal_ci/macos/grpc_distribtests.sh
index cf2ba090176..919121b6591 100644
--- a/tools/internal_ci/macos/grpc_distribtests.sh
+++ b/tools/internal_ci/macos/grpc_distribtests.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
@@ -26,11 +29,4 @@ source tools/internal_ci/helper_scripts/prepare_build_macos_rc
 mv ${KOKORO_GFILE_DIR}/github/grpc/artifacts input_artifacts || true
 ls -R input_artifacts || true
 
-tools/run_tests/task_runner.py -f distribtest macos || FAILED="true"
-
-tools/internal_ci/helper_scripts/delete_nonartifacts.sh || true
-
-if [ "$FAILED" != "" ]
-then
-  exit 1
-fi
+tools/run_tests/task_runner.py -f distribtest macos
diff --git a/tools/internal_ci/macos/grpc_distribtests_php.sh b/tools/internal_ci/macos/grpc_distribtests_php.sh
index a6c33285d79..5bd716c32fc 100644
--- a/tools/internal_ci/macos/grpc_distribtests_php.sh
+++ b/tools/internal_ci/macos/grpc_distribtests_php.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
@@ -39,7 +42,7 @@ cp -r artifacts/php_pecl_package_macos_*/* input_artifacts/ || true
 # a better signal about which distribtest are affected by the currently broken artifact builds.
 tools/run_tests/task_runner.py -f distribtest macos php -j 4 -x distribtests/sponge_log.xml || FAILED="true"
 
-tools/internal_ci/helper_scripts/delete_nonartifacts.sh || true
+tools/internal_ci/helper_scripts/store_artifacts_from_moved_src_tree.sh
 
 if [ "$FAILED" != "" ]
 then
diff --git a/tools/internal_ci/macos/grpc_interop_toprod.sh b/tools/internal_ci/macos/grpc_interop_toprod.sh
index c4d300d4a9b..962a37d8eb5 100755
--- a/tools/internal_ci/macos/grpc_interop_toprod.sh
+++ b/tools/internal_ci/macos/grpc_interop_toprod.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
@@ -41,8 +44,6 @@ tools/run_tests/run_interop_tests.py -l c++ \
     --default_service_account="interop-to-prod-tests@grpc-testing.iam.gserviceaccount.com" \
     --skip_compute_engine_creds --internal_ci -t -j 4 || FAILED="true"
 
-tools/internal_ci/helper_scripts/delete_nonartifacts.sh || true
-
 if [ "$FAILED" != "" ]
 then
   exit 1
diff --git a/tools/internal_ci/macos/grpc_ios_binary_size.sh b/tools/internal_ci/macos/grpc_ios_binary_size.sh
index 523e3ae8b7d..66b098dfa2a 100755
--- a/tools/internal_ci/macos/grpc_ios_binary_size.sh
+++ b/tools/internal_ci/macos/grpc_ios_binary_size.sh
@@ -16,6 +16,9 @@
 # This script is invoked by Jenkins and runs a diff on the microbenchmarks
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # List of benchmarks that provide good signal for analyzing performance changes in pull requests
 
 # Enter the gRPC repo root
diff --git a/tools/internal_ci/macos/grpc_run_bazel_c_cpp_tests.sh b/tools/internal_ci/macos/grpc_run_bazel_c_cpp_tests.sh
index 194f273f675..01f34e0e3ff 100644
--- a/tools/internal_ci/macos/grpc_run_bazel_c_cpp_tests.sh
+++ b/tools/internal_ci/macos/grpc_run_bazel_c_cpp_tests.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
diff --git a/tools/internal_ci/macos/grpc_run_bazel_core_ios_tests.sh b/tools/internal_ci/macos/grpc_run_bazel_core_ios_tests.sh
index fa33aa45079..68e96d7af08 100644
--- a/tools/internal_ci/macos/grpc_run_bazel_core_ios_tests.sh
+++ b/tools/internal_ci/macos/grpc_run_bazel_core_ios_tests.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
diff --git a/tools/internal_ci/macos/grpc_run_bazel_cpp_ios_tests.sh b/tools/internal_ci/macos/grpc_run_bazel_cpp_ios_tests.sh
index c6523408040..0acd139bcef 100644
--- a/tools/internal_ci/macos/grpc_run_bazel_cpp_ios_tests.sh
+++ b/tools/internal_ci/macos/grpc_run_bazel_cpp_ios_tests.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
diff --git a/tools/internal_ci/macos/grpc_run_bazel_isolated_tests.sh b/tools/internal_ci/macos/grpc_run_bazel_isolated_tests.sh
index e213105d61d..c137d382911 100644
--- a/tools/internal_ci/macos/grpc_run_bazel_isolated_tests.sh
+++ b/tools/internal_ci/macos/grpc_run_bazel_isolated_tests.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
diff --git a/tools/internal_ci/macos/grpc_run_tests_matrix.sh b/tools/internal_ci/macos/grpc_run_tests_matrix.sh
index b74508b7eb0..fcb27d3ee1f 100755
--- a/tools/internal_ci/macos/grpc_run_tests_matrix.sh
+++ b/tools/internal_ci/macos/grpc_run_tests_matrix.sh
@@ -15,6 +15,9 @@
 
 set -ex
 
+# avoid slow finalization after the script has exited.
+source $(dirname $0)/../../../tools/internal_ci/helper_scripts/move_src_tree_and_respawn_itself_rc
+
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
@@ -25,8 +28,6 @@ tools/run_tests/run_tests_matrix.py $RUN_TESTS_FLAGS || FAILED="true"
 # kill port_server.py to prevent the build from freezing
 ps aux | grep port_server\\.py | awk '{print $2}' | xargs kill -9
 
-tools/internal_ci/helper_scripts/delete_nonartifacts.sh || true
-
 if [ "$FAILED" != "" ]
 then
   exit 1
diff --git a/tools/internal_ci/windows/bazel_rbe.bat b/tools/internal_ci/windows/bazel_rbe.bat
index 3fd021b3ef4..acf0076d872 100644
--- a/tools/internal_ci/windows/bazel_rbe.bat
+++ b/tools/internal_ci/windows/bazel_rbe.bat
@@ -12,6 +12,13 @@
 @rem See the License for the specific language governing permissions and
 @rem limitations under the License.
 
+@rem Avoid slow finalization after the script has exited.
+@rem See the script's prologue for info on the correct invocation pattern.
+IF "%cd%"=="T:\src" (
+  call %~dp0\..\..\..\tools\internal_ci\helper_scripts\move_src_tree_and_respawn_itself.bat %0
+  exit /b %errorlevel%
+)
+
 @rem TODO(jtattermusch): make this generate less output
 @rem TODO(jtattermusch): use tools/bazel script to keep the versions in sync
 choco install bazel -y --version 4.2.1 --limit-output
diff --git a/tools/internal_ci/windows/grpc_build_artifacts.bat b/tools/internal_ci/windows/grpc_build_artifacts.bat
index b8901e384cf..72813bd4b59 100644
--- a/tools/internal_ci/windows/grpc_build_artifacts.bat
+++ b/tools/internal_ci/windows/grpc_build_artifacts.bat
@@ -12,6 +12,13 @@
 @rem See the License for the specific language governing permissions and
 @rem limitations under the License.
 
+@rem Avoid slow finalization after the script has exited.
+@rem See the script's prologue for info on the correct invocation pattern.
+IF "%cd%"=="T:\src" (
+  call %~dp0\..\..\..\tools\internal_ci\helper_scripts\move_src_tree_and_respawn_itself.bat %0
+  exit /b %errorlevel%
+)
+
 @rem Boringssl build no longer supports yasm
 choco uninstall yasm -y --limit-output
 choco install nasm -y --limit-output
@@ -25,6 +32,6 @@ call tools/internal_ci/helper_scripts/prepare_build_windows.bat || exit /b 1
 python tools/run_tests/task_runner.py -f artifact windows -j 4
 set RUNTESTS_EXITCODE=%errorlevel%
 
-bash tools/internal_ci/helper_scripts/delete_nonartifacts.sh
+bash tools/internal_ci/helper_scripts/store_artifacts_from_moved_src_tree.sh
 
 exit /b %RUNTESTS_EXITCODE%
diff --git a/tools/internal_ci/windows/grpc_build_packages.bat b/tools/internal_ci/windows/grpc_build_packages.bat
index 8f1e5794e29..42d2346f77d 100644
--- a/tools/internal_ci/windows/grpc_build_packages.bat
+++ b/tools/internal_ci/windows/grpc_build_packages.bat
@@ -12,6 +12,13 @@
 @rem See the License for the specific language governing permissions and
 @rem limitations under the License.
 
+@rem Avoid slow finalization after the script has exited.
+@rem See the script's prologue for info on the correct invocation pattern.
+IF "%cd%"=="T:\src" (
+  call %~dp0\..\..\..\tools\internal_ci\helper_scripts\move_src_tree_and_respawn_itself.bat %0
+  exit /b %errorlevel%
+)
+
 @rem enter repo root
 cd /d %~dp0\..\..\..
 
@@ -24,6 +31,4 @@ rem The only build_packages task that ever needed to run on windows was C#, but
 rem building C# nugets on linux (as dotnet SDK on linux does a good job)
 rem TODO(jtattermusch): remove the infrastructure for running "build_packages" kokoro job on windows.
 
-bash tools/internal_ci/helper_scripts/delete_nonartifacts.sh
-
 exit /b %RUNTESTS_EXITCODE%
diff --git a/tools/internal_ci/windows/grpc_distribtests.bat b/tools/internal_ci/windows/grpc_distribtests.bat
index 6b74972f359..5d1051860b2 100644
--- a/tools/internal_ci/windows/grpc_distribtests.bat
+++ b/tools/internal_ci/windows/grpc_distribtests.bat
@@ -12,6 +12,13 @@
 @rem See the License for the specific language governing permissions and
 @rem limitations under the License.
 
+@rem Avoid slow finalization after the script has exited.
+@rem See the script's prologue for info on the correct invocation pattern.
+IF "%cd%"=="T:\src" (
+  call %~dp0\..\..\..\tools\internal_ci\helper_scripts\move_src_tree_and_respawn_itself.bat %0
+  exit /b %errorlevel%
+)
+
 @rem enter repo root
 cd /d %~dp0\..\..\..
 
@@ -24,6 +31,4 @@ dir input_artifacts
 python tools/run_tests/task_runner.py -f distribtest windows -j 4
 set RUNTESTS_EXITCODE=%errorlevel%
 
-bash tools/internal_ci/helper_scripts/delete_nonartifacts.sh
-
 exit /b %RUNTESTS_EXITCODE%
diff --git a/tools/internal_ci/windows/grpc_distribtests_standalone.bat b/tools/internal_ci/windows/grpc_distribtests_standalone.bat
index e0722dbf375..1d0635723f3 100644
--- a/tools/internal_ci/windows/grpc_distribtests_standalone.bat
+++ b/tools/internal_ci/windows/grpc_distribtests_standalone.bat
@@ -12,6 +12,13 @@
 @rem See the License for the specific language governing permissions and
 @rem limitations under the License.
 
+@rem Avoid slow finalization after the script has exited.
+@rem See the script's prologue for info on the correct invocation pattern.
+IF "%cd%"=="T:\src" (
+  call %~dp0\..\..\..\tools\internal_ci\helper_scripts\move_src_tree_and_respawn_itself.bat %0
+  exit /b %errorlevel%
+)
+
 @rem enter repo root
 cd /d %~dp0\..\..\..
 
@@ -20,6 +27,4 @@ call tools/internal_ci/helper_scripts/prepare_build_windows.bat || exit /b 1
 python tools/run_tests/task_runner.py -f distribtest windows cpp -j 4
 set RUNTESTS_EXITCODE=%errorlevel%
 
-bash tools/internal_ci/helper_scripts/delete_nonartifacts.sh
-
 exit /b %RUNTESTS_EXITCODE%
diff --git a/tools/internal_ci/windows/grpc_run_tests_matrix.bat b/tools/internal_ci/windows/grpc_run_tests_matrix.bat
index cd410a51ef3..c13386d88d5 100644
--- a/tools/internal_ci/windows/grpc_run_tests_matrix.bat
+++ b/tools/internal_ci/windows/grpc_run_tests_matrix.bat
@@ -12,6 +12,13 @@
 @rem See the License for the specific language governing permissions and
 @rem limitations under the License.
 
+@rem Avoid slow finalization after the script has exited.
+@rem See the script's prologue for info on the correct invocation pattern.
+IF "%cd%"=="T:\src" (
+  call %~dp0\..\..\..\tools\internal_ci\helper_scripts\move_src_tree_and_respawn_itself.bat %0
+  exit /b %errorlevel%
+)
+
 @rem enter repo root
 cd /d %~dp0\..\..\..
 
@@ -28,6 +35,4 @@ python3 tools/run_tests/start_port_server.py
 python3 tools/run_tests/run_tests_matrix.py %RUN_TESTS_FLAGS%
 set RUNTESTS_EXITCODE=%errorlevel%
 
-bash tools/internal_ci/helper_scripts/delete_nonartifacts.sh
-
 exit /b %RUNTESTS_EXITCODE%
diff --git a/tools/run_tests/dockerize/build_docker_and_run_tests.sh b/tools/run_tests/dockerize/build_docker_and_run_tests.sh
index 4a7908b0462..74626e54fb6 100755
--- a/tools/run_tests/dockerize/build_docker_and_run_tests.sh
+++ b/tools/run_tests/dockerize/build_docker_and_run_tests.sh
@@ -81,7 +81,13 @@ docker run \
 # run_tests.py runs 
 TEMP_REPORTS_ZIP=$(mktemp)
 docker cp "$CONTAINER_NAME:/var/local/git/grpc/reports.zip" "${TEMP_REPORTS_ZIP}" || true
-unzip -o "${TEMP_REPORTS_ZIP}" -d "$git_root" || true
+if [ "${GRPC_TEST_REPORT_BASE_DIR}" != "" ]
+then
+  REPORTS_DEST_DIR="${GRPC_TEST_REPORT_BASE_DIR}"
+else
+  REPORTS_DEST_DIR="${git_root}"
+fi
+unzip -o "${TEMP_REPORTS_ZIP}" -d "${REPORTS_DEST_DIR}" || true
 rm -f "${TEMP_REPORTS_ZIP}"
 
 # remove the container, possibly killing it first
diff --git a/tools/run_tests/python_utils/report_utils.py b/tools/run_tests/python_utils/report_utils.py
index ffc59e8d984..5cf7851b5f0 100644
--- a/tools/run_tests/python_utils/report_utils.py
+++ b/tools/run_tests/python_utils/report_utils.py
@@ -80,6 +80,10 @@ def render_junit_xml_report(resultset,
 
 def create_xml_report_file(tree, report_file):
     """Generate JUnit-like report file from xml tree ."""
+    # env variable can be used to override the base location for the reports
+    base_dir = os.getenv('GRPC_TEST_REPORT_BASE_DIR', None)
+    if base_dir:
+        report_file = os.path.join(base_dir, report_file)
     # ensure the report directory exists
     report_dir = os.path.dirname(os.path.abspath(report_file))
     if not os.path.exists(report_dir):
diff --git a/tools/run_tests/run_tests_matrix.py b/tools/run_tests/run_tests_matrix.py
index 29adeb40520..664d313c13b 100755
--- a/tools/run_tests/run_tests_matrix.py
+++ b/tools/run_tests/run_tests_matrix.py
@@ -62,8 +62,14 @@ def _matrix_job_logfilename(shortname_for_multi_target):
     # for the corresponding 'sponge_log.xml' report.
     # the shortname_for_multi_target component must be set to match the sponge_log.xml location
     # because the top-level render_junit_xml_report is called with multi_target=True
-    return '%s/%s/%s' % (_MATRIX_REPORT_NAME, shortname_for_multi_target,
-                         'sponge_log.log')
+    sponge_log_name = '%s/%s/%s' % (
+        _MATRIX_REPORT_NAME, shortname_for_multi_target, 'sponge_log.log')
+    # env variable can be used to override the base location for the reports
+    # so we need to match that behavior here too
+    base_dir = os.getenv('GRPC_TEST_REPORT_BASE_DIR', None)
+    if base_dir:
+        sponge_log_name = os.path.join(base_dir, sponge_log_name)
+    return sponge_log_name
 
 
 def _docker_jobspec(name,
@@ -102,11 +108,15 @@ def _workspace_jobspec(name,
     shortname = 'run_tests_%s' % name
     env = {'WORKSPACE_NAME': workspace_name}
     env.update(runtests_envs)
+    # if report base dir is set, we don't need to ".." to come out of the workspace dir
+    report_dir_prefix = '' if os.getenv('GRPC_TEST_REPORT_BASE_DIR',
+                                        None) else '../'
     test_job = jobset.JobSpec(cmdline=[
         'bash', 'tools/run_tests/helper_scripts/run_tests_in_workspace.sh',
         '-t', '-j',
         str(inner_jobs), '-x',
-        '../run_tests/%s' % _report_filename(name), '--report_suite_name',
+        '%srun_tests/%s' %
+        (report_dir_prefix, _report_filename(name)), '--report_suite_name',
         '%s' % _safe_report_name(name)
     ] + runtests_args,
                               environ=env,