diff --git a/.buildkite/commands/run-unit-tests.sh b/.buildkite/commands/run-unit-tests.sh
index c8ee2cf56788..fa7b763f9d9c 100755
--- a/.buildkite/commands/run-unit-tests.sh
+++ b/.buildkite/commands/run-unit-tests.sh
@@ -4,15 +4,18 @@ echo "--- 🧪 Testing"
 set +e
 if [ "$1" == "wordpress" ]; then
     test_suite="testWordpressVanillaRelease koverXmlReportWordpressVanillaRelease"
-    test_log_dir="WordPress/build/test-results/*/*.xml"
+    test_results_dir="WordPress/build/test-results"
+    test_log_dir="${test_results_dir}/*/*.xml"
     code_coverage_report="WordPress/build/reports/kover/reportWordpressVanillaRelease.xml"
 elif [ "$1" == "processors" ]; then
     test_suite=":libs:processors:test :libs:processors:koverXmlReport"
-    test_log_dir="libs/processors/build/test-results/test/*.xml"
+    test_results_dir="libs/processors/build/test-results"
+    test_log_dir="${test_results_dir}/test/*.xml"
     code_coverage_report="libs/processors/build/reports/kover/report.xml"
 elif [ "$1" == "image-editor" ]; then
     test_suite=":libs:image-editor:testReleaseUnitTest :libs:image-editor:koverXmlReportRelease"
-    test_log_dir="libs/image-editor/build/test-results/testReleaseUnitTest/*.xml"
+    test_results_dir="libs/image-editor/build/test-results"
+    test_log_dir="${test_results_dir}/testReleaseUnitTest/*.xml"
     code_coverage_report="libs/image-editor/build/reports/kover/reportRelease.xml"
 else
     echo "Invalid Test Suite! Expected 'wordpress', 'processors', or 'image-editor', received '$1' instead"
@@ -31,23 +34,20 @@ if [[ "$TESTS_EXIT_STATUS" -ne 0 ]]; then
 fi
 
 echo "--- 🚦 Report Tests Status"
-path_pattern="*/build/test-results/*/*.xml"
-results_files=()
-while IFS= read -r -d '' file; do
-  results_files+=("$file")
-done < <(find . -path "$path_pattern" -type f -name "*.xml" -print0)
-
-for file in "${results_files[@]}"; do
-  if [[ $BUILDKITE_BRANCH == trunk ]] || [[ $BUILDKITE_BRANCH == release/* ]]; then
-    annotate_test_failures "$file" --slack "build-and-ship"
-  else
-    annotate_test_failures "$file"
-  fi
-done
+results_file="$test_results_dir/merged-test-results.xml"
+
+# Merge JUnit results into a single file (for performance reasons with reporting)
+merge_junit_reports -d ${test_log_dir%/*} -o $results_file
+
+if [[ $BUILDKITE_BRANCH == trunk ]] || [[ $BUILDKITE_BRANCH == release/* ]]; then
+  annotate_test_failures "$results_file" --slack "build-and-ship"
+else
+  annotate_test_failures "$results_file"
+fi
 
 echo "--- 🧪 Copying test logs for test collector"
 mkdir buildkite-test-analytics
-cp $test_log_dir buildkite-test-analytics
+cp $results_file buildkite-test-analytics
 
 echo "--- ⚒️ Uploading code coverage"
 .buildkite/commands/upload-code-coverage.sh $code_coverage_report
diff --git a/.buildkite/pipeline.yml b/.buildkite/pipeline.yml
index 1dc4ba2f854a..54fb5526032a 100644
--- a/.buildkite/pipeline.yml
+++ b/.buildkite/pipeline.yml
@@ -85,7 +85,7 @@ steps:
               <<: *test_collector_common_params
               api-token-env-name: "BUILDKITE_ANALYTICS_TOKEN_UNIT_TESTS_WORDPRESS"
         artifact_paths:
-          - "**/build/test-results/*/*.xml"
+          - "**/build/test-results/merged-test-results.xml"
 
       - label: "🔬 Unit Test Processors"
         command: ".buildkite/commands/run-unit-tests.sh processors"
@@ -95,7 +95,7 @@ steps:
               <<: *test_collector_common_params
               api-token-env-name: "BUILDKITE_ANALYTICS_TOKEN_UNIT_TESTS_PROCESSORS"
         artifact_paths:
-          - "**/build/test-results/*/*.xml"
+          - "**/build/test-results/merged-test-results.xml"
 
       - label: "🔬 Unit Test Image Editor"
         command: ".buildkite/commands/run-unit-tests.sh image-editor"
@@ -105,7 +105,7 @@ steps:
               <<: *test_collector_common_params
               api-token-env-name: "BUILDKITE_ANALYTICS_TOKEN_UNIT_TESTS_IMAGE_EDITOR"
         artifact_paths:
-          - "**/build/test-results/*/*.xml"
+          - "**/build/test-results/merged-test-results.xml"
 
   #################
   # Instrumented (aka UI) Tests
diff --git a/.buildkite/shared-pipeline-vars b/.buildkite/shared-pipeline-vars
index 2dbbc02e7912..00e32e0923c8 100644
--- a/.buildkite/shared-pipeline-vars
+++ b/.buildkite/shared-pipeline-vars
@@ -3,5 +3,5 @@
  # This file is `source`'d before calling `buildkite-agent pipeline upload`, and can be used
  # to set up some variables that will be interpolated in the `.yml` pipeline before uploading it.
 
- export CI_TOOLKIT="automattic/a8c-ci-toolkit#3.4.2"
+ export CI_TOOLKIT="automattic/a8c-ci-toolkit#3.5.0"
  export TEST_COLLECTOR="test-collector#v1.10.1"