diff --git a/bin/split-repo-post-process.sh b/bin/split-repo-post-process.sh
index a8e6de6b5f59..d1168f7272cc 100755
--- a/bin/split-repo-post-process.sh
+++ b/bin/split-repo-post-process.sh
@@ -167,7 +167,7 @@ if [[ "\${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "\${DIFF_RANGE}" -- "\${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "\${DIFF_RANGE}" -- ":(top)\${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in \${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -190,8 +190,6 @@ else
 fi
 
 
-echo "Fixing .trampolinerc for populate-secrets.sh"
-gsed -i 's|source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh|source ${PROJECT_ROOT}/'"${PACKAGE_PATH}"'/.kokoro/populate-secrets.sh|' "${PACKAGE_PATH}"/.trampolinerc
  
 # add changes to local git directory
 git add .
diff --git a/core/common/.kokoro/trampoline_v2.sh b/core/common/.kokoro/trampoline_v2.sh
index a489702c20c7..97222a73da72 100755
--- a/core/common/.kokoro/trampoline_v2.sh
+++ b/core/common/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/core/common"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/core/common/.trampolinerc b/core/common/.trampolinerc
index a03c8d1af836..5fc2253137db 100644
--- a/core/common/.trampolinerc
+++ b/core/common/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/core/common/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/core/paginator/.kokoro/trampoline_v2.sh b/core/paginator/.kokoro/trampoline_v2.sh
index 1fdd89c90802..7b2b14902656 100755
--- a/core/paginator/.kokoro/trampoline_v2.sh
+++ b/core/paginator/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/core/paginator"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/core/paginator/.trampolinerc b/core/paginator/.trampolinerc
index 9b4f78ac8be5..5fc2253137db 100644
--- a/core/paginator/.trampolinerc
+++ b/core/paginator/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/core/paginator/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/core/precise-date/.kokoro/trampoline_v2.sh b/core/precise-date/.kokoro/trampoline_v2.sh
index 9db7f49f00af..a9e80657cf7b 100755
--- a/core/precise-date/.kokoro/trampoline_v2.sh
+++ b/core/precise-date/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/core/precise-date"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/core/precise-date/.trampolinerc b/core/precise-date/.trampolinerc
index f968f490e685..5fc2253137db 100644
--- a/core/precise-date/.trampolinerc
+++ b/core/precise-date/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/core/precise-date/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/core/projectify/.kokoro/trampoline_v2.sh b/core/projectify/.kokoro/trampoline_v2.sh
index f6a5f9ab9b5c..28035da14d19 100755
--- a/core/projectify/.kokoro/trampoline_v2.sh
+++ b/core/projectify/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/core/projectify"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/core/projectify/.trampolinerc b/core/projectify/.trampolinerc
index 6d691505b3f6..5fc2253137db 100644
--- a/core/projectify/.trampolinerc
+++ b/core/projectify/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/core/projectify/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/core/promisify/.kokoro/trampoline_v2.sh b/core/promisify/.kokoro/trampoline_v2.sh
index 3cbeae9261a2..073e3766384e 100755
--- a/core/promisify/.kokoro/trampoline_v2.sh
+++ b/core/promisify/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/core/promisify"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/core/promisify/.trampolinerc b/core/promisify/.trampolinerc
index 91b558756655..5fc2253137db 100644
--- a/core/promisify/.trampolinerc
+++ b/core/promisify/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/core/promisify/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/bigquery-storage/.kokoro/trampoline_v2.sh b/handwritten/bigquery-storage/.kokoro/trampoline_v2.sh
index 92312d4d09c6..e6c1448bf86e 100755
--- a/handwritten/bigquery-storage/.kokoro/trampoline_v2.sh
+++ b/handwritten/bigquery-storage/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/handwritten/bigquery-storage"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/handwritten/bigquery-storage/.trampolinerc b/handwritten/bigquery-storage/.trampolinerc
index 7a2bd550b020..5fc2253137db 100644
--- a/handwritten/bigquery-storage/.trampolinerc
+++ b/handwritten/bigquery-storage/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/bigquery-storage/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/bigquery/.kokoro/trampoline_v2.sh b/handwritten/bigquery/.kokoro/trampoline_v2.sh
index 7a219c425ddf..c41ceac967d8 100755
--- a/handwritten/bigquery/.kokoro/trampoline_v2.sh
+++ b/handwritten/bigquery/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))"/handwritten/bigquery
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/handwritten/bigquery/.trampolinerc b/handwritten/bigquery/.trampolinerc
index 608c0961662a..c4f630fa614f 100644
--- a/handwritten/bigquery/.trampolinerc
+++ b/handwritten/bigquery/.trampolinerc
@@ -51,4 +51,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/bigquery/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/bigquery/src/types.d.ts b/handwritten/bigquery/src/types.d.ts
index 0322dfbdee0f..709c5a23614f 100644
--- a/handwritten/bigquery/src/types.d.ts
+++ b/handwritten/bigquery/src/types.d.ts
@@ -13,7 +13,7 @@
 // limitations under the License.
 
 /**
- * Discovery Revision: 20260328
+ * Discovery Revision: 20260429
  */
 
 /**
@@ -891,6 +891,16 @@ declare namespace bigquery {
     dataMaskingApplied?: boolean;
   };
 
+  /**
+   * A list of data policy options. For more information, see [Mask data by applying data policies to a column](https://docs.cloud.google.com/bigquery/docs/column-data-masking#data-policies-on-column).
+   */
+  type IDataPolicyList = {
+    /**
+     * Contains a list of data policy options. At most 9 data policies are allowed per field.
+     */
+    dataPolicies?: Array<IDataPolicyOption>;
+  };
+
   /**
    * Data policy option. For more information, see [Mask data by applying data policies to a column](https://docs.cloud.google.com/bigquery/docs/column-data-masking#data-policies-on-column).
    */
@@ -1787,6 +1797,10 @@ declare namespace bigquery {
      * Optional. Amount of memory provisioned for a Python UDF container instance. Format: {number}{unit} where unit is one of "M", "G", "Mi" and "Gi" (e.g. 1G, 512Mi). If not specified, the default value is 512Mi. For more information, see [Configure container limits for Python UDFs](https://cloud.google.com/bigquery/docs/user-defined-functions-python#configure-container-limits)
      */
     containerMemory?: string;
+    /**
+     * Optional. Maximum number of requests that a Cloud Run instance can handle concurrently. If absent or if `0`, a default concurrency is used.
+     */
+    containerRequestConcurrency?: string;
     /**
      * Optional. Maximum number of rows in each batch sent to the external runtime. If absent or if 0, BigQuery dynamically decides the number of rows in a batch.
      */
@@ -1883,6 +1897,16 @@ declare namespace bigquery {
     errors?: Array<string>;
   };
 
+  /**
+   * Provides cache statistics for a GenAi function call.
+   */
+  type IGenAiFunctionCacheStats = {
+    /**
+     * Number of rows served from cache.
+     */
+    numCacheHitRows?: string;
+  };
+
   /**
    * Provides cost optimization statistics for a GenAi function call.
    */
@@ -1915,6 +1939,10 @@ declare namespace bigquery {
    * Provides statistics for each Ai function call within a query.
    */
   type IGenAiFunctionStats = {
+    /**
+     * Cache stats for the function.
+     */
+    cacheStats?: IGenAiFunctionCacheStats;
     /**
      * Cost optimization stats if applied on the rows processed by the function.
      */
@@ -3728,6 +3756,20 @@ declare namespace bigquery {
     refreshWatermark?: string;
   };
 
+  /**
+   * Column Metadata Index staleness detailed infnormation.
+   */
+  type IMetadataCacheStalenessInsight = {
+    /**
+     * Output only. Average column metadata index staleness of previous runs with the same query hash.
+     */
+    avgPreviousStalenessMs?: string;
+    /**
+     * Output only. The percent increase in staleness between the current job and the average staleness of previous jobs with the same query hash.
+     */
+    stalenessPercentageIncrease?: number;
+  };
+
   /**
    * Statistics for metadata caching in queried tables.
    */
@@ -4027,6 +4069,10 @@ declare namespace bigquery {
      * Output only. Standalone query stage performance insights, for exploring potential improvements.
      */
     stagePerformanceStandaloneInsights?: Array<IStagePerformanceStandaloneInsight>;
+    /**
+     * Output only. Performance insights for table-level attributes that changed compared to previous runs.
+     */
+    tableChangeInsights?: Array<ITableChangeInsight>;
   };
 
   /**
@@ -5576,6 +5622,24 @@ declare namespace bigquery {
 
   type ITableCell = {v?: any};
 
+  /**
+   * Table-level performance insights compared to previous runs. These insights don't apply to specific query stages, rather they apply to the whole table.
+   */
+  type ITableChangeInsight = {
+    /**
+     * Output only. True if the table's column metadata index was not used in the current job, but was used in a previous job with the same query hash.
+     */
+    metadataCacheNotUsedButUsedPreviously?: boolean;
+    /**
+     * Output only. If present, indicates that the table's metadata column index staleness has increased significantly compared to previous jobs with the same query hash.
+     */
+    metadataCacheStalenessInsight?: IMetadataCacheStalenessInsight;
+    /**
+     * Output only. The table that was queried.
+     */
+    tableReference?: ITableReference;
+  };
+
   /**
    * The TableConstraints defines the primary key and foreign key.
    */
@@ -5717,10 +5781,23 @@ declare namespace bigquery {
      * Optional. Field collation can be set only when the type of field is STRING. The following values are supported: * 'und:ci': undetermined locale, case insensitive. * '': empty string. Default to case-sensitive behavior.
      */
     collation?: string;
+    /**
+     * Optional. Specifies the data governance tags on this field. This field works with other column-level security fields as follows: - Precedence: If a data governance tag is attached to a column, it takes precedence over the policy tag attached to the column. However, if a data policy is attached to a column, it takes precedence over the data governance tag. - Patching behavior (how this field behaves during a `Table.patch` schema update): - Unset: If the `data_governance_tags_info` field is omitted from the update request, the existing tags on the column are preserved. - Empty Field: To clear data governance tags from a column, send the `data_governance_tags_info` field as an empty object. This will remove all tags from the column. - Updating tags: To replace existing tag, send the field with the new tag.
+     */
+    dataGovernanceTagsInfo?: {
+      /**
+       * Optional. The data governance tags added to this field are used for field-level access control. Only one data governance tag is currently supported on a field. Tag keys are globally unique. Tag key is expected to be in the namespaced format, for example "123456789012/pii" where 123456789012 is the ID of the parent organization or project resource for this tag key. Tag value is expected to be the short name, for example "sensitive". See [Tag definitions](https://cloud.google.com/iam/docs/tags-access-control#definitions) for more details. For example: "123456789012/pii": "sensitive", "myProject/cost_center": "sales"
+       */
+      dataGovernanceTags?: {[key: string]: string};
+    };
     /**
      * Optional. Data policies attached to this field, used for field-level access control.
      */
     dataPolicies?: Array<IDataPolicyOption>;
+    /**
+     * Optional. Specifies data policies attached to this field, used for field-level access control. When set, this will be the source of truth for data policy information.
+     */
+    dataPolicyList?: IDataPolicyList;
     /**
      * Optional. A SQL expression to specify the [default value] (https://cloud.google.com/bigquery/docs/default-values) for this field.
      */
diff --git a/handwritten/bigtable/.kokoro/trampoline_v2.sh b/handwritten/bigtable/.kokoro/trampoline_v2.sh
index 0a0238900394..942a2d678202 100755
--- a/handwritten/bigtable/.kokoro/trampoline_v2.sh
+++ b/handwritten/bigtable/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/handwritten/bigtable"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/handwritten/bigtable/.trampolinerc b/handwritten/bigtable/.trampolinerc
index a38a309cd7ef..5fc2253137db 100644
--- a/handwritten/bigtable/.trampolinerc
+++ b/handwritten/bigtable/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/bigtable/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/cloud-profiler/.trampolinerc b/handwritten/cloud-profiler/.trampolinerc
index ad15983af29c..5fc2253137db 100644
--- a/handwritten/cloud-profiler/.trampolinerc
+++ b/handwritten/cloud-profiler/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/cloud-profiler/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/datastore/.kokoro/trampoline_v2.sh b/handwritten/datastore/.kokoro/trampoline_v2.sh
index 8b3b225e110e..aa09b88f7021 100755
--- a/handwritten/datastore/.kokoro/trampoline_v2.sh
+++ b/handwritten/datastore/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/handwritten/datastore"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/handwritten/datastore/.trampolinerc b/handwritten/datastore/.trampolinerc
index a085b321d44b..5fc2253137db 100644
--- a/handwritten/datastore/.trampolinerc
+++ b/handwritten/datastore/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/datastore/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/error-reporting/.kokoro/trampoline_v2.sh b/handwritten/error-reporting/.kokoro/trampoline_v2.sh
index 9c03d000c1f9..f4e7a9378588 100755
--- a/handwritten/error-reporting/.kokoro/trampoline_v2.sh
+++ b/handwritten/error-reporting/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/handwritten/error-reporting"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/handwritten/error-reporting/.trampolinerc b/handwritten/error-reporting/.trampolinerc
index bec8dd85c29f..5fc2253137db 100644
--- a/handwritten/error-reporting/.trampolinerc
+++ b/handwritten/error-reporting/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/error-reporting/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/firestore/.kokoro/trampoline.sh b/handwritten/firestore/.kokoro/trampoline.sh
index ef9cb4a426d6..bc983bd3c2b1 100755
--- a/handwritten/firestore/.kokoro/trampoline.sh
+++ b/handwritten/firestore/.kokoro/trampoline.sh
@@ -13,7 +13,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
diff --git a/handwritten/firestore/.trampolinerc b/handwritten/firestore/.trampolinerc
index 2af668a017d0..5fc2253137db 100644
--- a/handwritten/firestore/.trampolinerc
+++ b/handwritten/firestore/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/firestore/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/logging-bunyan/.kokoro/trampoline_v2.sh b/handwritten/logging-bunyan/.kokoro/trampoline_v2.sh
index b13a2f79d69b..7353696416d0 100755
--- a/handwritten/logging-bunyan/.kokoro/trampoline_v2.sh
+++ b/handwritten/logging-bunyan/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/handwritten/logging-bunyan"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/handwritten/logging-bunyan/.trampolinerc b/handwritten/logging-bunyan/.trampolinerc
index 5dac5eade264..5fc2253137db 100644
--- a/handwritten/logging-bunyan/.trampolinerc
+++ b/handwritten/logging-bunyan/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/logging-bunyan/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/logging-winston/.kokoro/trampoline_v2.sh b/handwritten/logging-winston/.kokoro/trampoline_v2.sh
index 44b77110d0e1..d530a93e704e 100755
--- a/handwritten/logging-winston/.kokoro/trampoline_v2.sh
+++ b/handwritten/logging-winston/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))"/handwritten/logging-winston
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/handwritten/logging-winston/.trampolinerc b/handwritten/logging-winston/.trampolinerc
index b0b7f3fcaa3f..5fc2253137db 100644
--- a/handwritten/logging-winston/.trampolinerc
+++ b/handwritten/logging-winston/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/logging-winston/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/logging/.kokoro/trampoline_v2.sh b/handwritten/logging/.kokoro/trampoline_v2.sh
index ce3e779c7889..720f5039eec3 100755
--- a/handwritten/logging/.kokoro/trampoline_v2.sh
+++ b/handwritten/logging/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/handwritten/logging"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/handwritten/logging/.trampolinerc b/handwritten/logging/.trampolinerc
index f1ac3ee1315e..e7bdc6334237 100644
--- a/handwritten/logging/.trampolinerc
+++ b/handwritten/logging/.trampolinerc
@@ -50,4 +50,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/logging/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/pubsub/.kokoro/trampoline_v2.sh b/handwritten/pubsub/.kokoro/trampoline_v2.sh
index 682bdefdb061..681e66947bd0 100755
--- a/handwritten/pubsub/.kokoro/trampoline_v2.sh
+++ b/handwritten/pubsub/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/handwritten/pubsub"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/handwritten/pubsub/.trampolinerc b/handwritten/pubsub/.trampolinerc
index a04ed00bb26c..5fc2253137db 100644
--- a/handwritten/pubsub/.trampolinerc
+++ b/handwritten/pubsub/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/pubsub/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/spanner/.kokoro/trampoline_v2.sh b/handwritten/spanner/.kokoro/trampoline_v2.sh
index 2ed993bbdff3..3982657992a5 100755
--- a/handwritten/spanner/.kokoro/trampoline_v2.sh
+++ b/handwritten/spanner/.kokoro/trampoline_v2.sh
@@ -254,9 +254,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/handwritten/spanner"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -269,7 +266,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -277,6 +274,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
@@ -511,3 +511,4 @@ if [[ "${update_cache}" == "true" ]] && \
 fi
 
 exit "${test_retval}"
+
diff --git a/handwritten/spanner/.trampolinerc b/handwritten/spanner/.trampolinerc
index dea7e9541e63..5fc2253137db 100644
--- a/handwritten/spanner/.trampolinerc
+++ b/handwritten/spanner/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/spanner/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh
diff --git a/handwritten/storage/.kokoro/trampoline_v2.sh b/handwritten/storage/.kokoro/trampoline_v2.sh
index e1adcd24e9e7..5a1817a48e89 100755
--- a/handwritten/storage/.kokoro/trampoline_v2.sh
+++ b/handwritten/storage/.kokoro/trampoline_v2.sh
@@ -251,9 +251,6 @@ else
     PROJECT_ROOT="$(repo_root $(pwd))/handwritten/storage"
 fi
 
-log_yellow "Changing to the project root: ${PROJECT_ROOT}."
-cd "${PROJECT_ROOT}"
-
 # Auto-injected conditional check
 # Check if the package directory has changes. If not, skip tests.
 if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
@@ -266,7 +263,7 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     # Safe default: HEAD~1..HEAD
     DIFF_RANGE="HEAD~1..HEAD"
 
-    if git diff --quiet "${DIFF_RANGE}" -- "${RELATIVE_PKG_PATH}"; then
+    if git diff --quiet "${DIFF_RANGE}" -- ":(top)${RELATIVE_PKG_PATH}"; then
         echo "No changes detected in ${RELATIVE_PKG_PATH}. Skipping tests."
         exit 0
     else
@@ -274,6 +271,9 @@ if [[ "${RUNNING_IN_CI:-}" == "true" ]]; then
     fi
 fi
 
+log_yellow "Changing to the project root: ${PROJECT_ROOT}."
+cd "${PROJECT_ROOT}"
+
 # To support relative path for `TRAMPOLINE_SERVICE_ACCOUNT`, we need
 # to use this environment variable in `PROJECT_ROOT`.
 if [[ -n "${TRAMPOLINE_SERVICE_ACCOUNT:-}" ]]; then
diff --git a/handwritten/storage/.trampolinerc b/handwritten/storage/.trampolinerc
index 2feed5b5844f..5fc2253137db 100644
--- a/handwritten/storage/.trampolinerc
+++ b/handwritten/storage/.trampolinerc
@@ -49,4 +49,4 @@ if [[ -z "${TRAMPOLINE_BUILD_FILE:-}" ]]; then
 fi
 
 # Secret Manager secrets.
-source ${PROJECT_ROOT}/handwritten/storage/.kokoro/populate-secrets.sh
+source ${PROJECT_ROOT}/.kokoro/populate-secrets.sh