diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c3824656..9fcd2699 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -76,7 +76,7 @@ stages:
     include:
       - local: '.gitlab/custom-jobs-and-variables.yml'
       - project: 'radiuss/radiuss-shared-ci'
-        ref: 'v2025.09.0'
+        ref: 'v2025.09.1'
         file: 'pipelines/${CI_MACHINE}.yml'
       - artifact: '${CI_MACHINE}-jobs.yml'
         job: 'generate-job-lists'
@@ -90,7 +90,7 @@ include:
     file: 'id_tokens.yml'
   # [Optional] checks preliminary to running the actual CI test
   - project: 'radiuss/radiuss-shared-ci'
-    ref: 'v2025.09.0'
+    ref: 'v2025.09.1'
     file: 'utilities/preliminary-ignore-draft-pr.yml'
   # pipelines subscribed by the project
   - local: '.gitlab/subscribed-pipelines.yml'
diff --git a/.gitlab/custom-jobs-and-variables.yml b/.gitlab/custom-jobs-and-variables.yml
index 6c7ef28b..e30e7e34 100644
--- a/.gitlab/custom-jobs-and-variables.yml
+++ b/.gitlab/custom-jobs-and-variables.yml
@@ -22,6 +22,16 @@ variables:
 # Project specific deps for dane
   PROJECT_DANE_DEPS: ""
 
+# Matrix
+# Arguments for top level allocation
+  MATRIX_SHARED_ALLOC: "--exclusive --partition=pci --time=10 --nodes=1"
+# Arguments for job level allocation
+  MATRIX_JOB_ALLOC: "--partition=pci --overlap --nodes=1"
+# Project specific variants for matrix
+  PROJECT_MATRIX_VARIANTS: "+tests ~papi +cuda cuda_arch=75"
+# Project specific deps for matrix
+  PROJECT_MATRIX_DEPS: ""
+
 # Corona
 # Arguments for top level allocation
   CORONA_SHARED_ALLOC: "--exclusive --time-limit=8m --nodes=1 -o per-resource.count=2"
diff --git a/.gitlab/jobs/matrix.yml b/.gitlab/jobs/matrix.yml
new file mode 100644
index 00000000..0b2ae7d4
--- /dev/null
+++ b/.gitlab/jobs/matrix.yml
@@ -0,0 +1,12 @@
+##############################################################################
+# Copyright (c) 2022-25, Lawrence Livermore National Security, LLC and RADIUSS
+# project contributors. See the COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (MIT)
+##############################################################################
+
+# Override reproducer section to define project specific variables.
+.matrix_reproducer_vars:
+  script:
+    - !reference [.reproducer_vars, script]
+
diff --git a/.gitlab/subscribed-pipelines.yml b/.gitlab/subscribed-pipelines.yml
index 3998590f..fe00fae0 100644
--- a/.gitlab/subscribed-pipelines.yml
+++ b/.gitlab/subscribed-pipelines.yml
@@ -38,6 +38,7 @@ generate-job-lists:
     LOCAL_JOBS_PATH: ".gitlab/jobs"
   script:
     - cat ${RADIUSS_JOBS_PATH}/dane.yml ${LOCAL_JOBS_PATH}/dane.yml > dane-jobs.yml
+    - cat ${RADIUSS_JOBS_PATH}/matrix.yml ${LOCAL_JOBS_PATH}/matrix.yml > matrix-jobs.yml
     - cat ${RADIUSS_JOBS_PATH}/lassen.yml ${LOCAL_JOBS_PATH}/lassen.yml > lassen-jobs.yml
     - cat ${RADIUSS_JOBS_PATH}/corona.yml ${LOCAL_JOBS_PATH}/corona.yml > corona-jobs.yml
     - cat ${RADIUSS_JOBS_PATH}/tioga.yml ${LOCAL_JOBS_PATH}/tioga.yml > tioga-jobs.yml
@@ -45,6 +46,7 @@ generate-job-lists:
   artifacts:
     paths:
       - dane-jobs.yml
+      - matrix-jobs.yml
       - lassen-jobs.yml
       - corona-jobs.yml
       - tioga-jobs.yml
@@ -72,6 +74,28 @@ dane-build-and-test:
       when: never
     - when: on_success
 
+# MATRIX
+matrix-up-check:
+  variables:
+    CI_MACHINE: "matrix"
+  extends: [.machine-check]
+  rules:
+    # Runs except if we explicitly deactivate matrix by variable.
+    - if: '$ON_MATRIX == "OFF"'
+      when: never
+    - when: on_success
+
+matrix-build-and-test:
+  variables:
+    CI_MACHINE: "matrix"
+  needs: [matrix-up-check, generate-job-lists]
+  extends: [.build-and-test]
+  rules:
+    # Runs except if we explicitly deactivate matrix by variable.
+    - if: '$ON_MATRIX == "OFF"'
+      when: never
+    - when: on_success
+
 # CORONA
 corona-up-check:
   variables:
diff --git a/scripts/gitlab/build-and-test.sh b/scripts/gitlab/build-and-test.sh
index 6c93e4b6..268eccd2 100755
--- a/scripts/gitlab/build-and-test.sh
+++ b/scripts/gitlab/build-and-test.sh
@@ -194,7 +194,7 @@ then
     timed_message "Cleaning working directory"
 
     # Map CPU core allocations
-    declare -A core_counts=(["lassen"]=40 ["dane"]=28 ["corona"]=32 ["rzansel"]=48 ["tioga"]=32 ["tuolumne"]=48)
+    declare -A core_counts=(["lassen"]=40 ["dane"]=28 ["matrix"]=28 ["corona"]=32 ["rzansel"]=48 ["tioga"]=32 ["tuolumne"]=48)
 
     # If building, then delete everything first
     # NOTE: 'cmake --build . -j core_counts' attempts to reduce individual build resources.
diff --git a/scripts/radiuss-spack-configs b/scripts/radiuss-spack-configs
index b39030f6..2b1f50d1 160000
--- a/scripts/radiuss-spack-configs
+++ b/scripts/radiuss-spack-configs
@@ -1 +1 @@
-Subproject commit b39030f680263f6c15c7dfe510fa6ffdb9482136
+Subproject commit 2b1f50d135a497b06e29b9065fc50baf9766283c