diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index c6b88a70d..ffe1cbcee 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -59,7 +59,6 @@ jobs:
     name: Integration test charm
     needs:
       - lint
-      - unit-test
       - build
     uses: ./.github/workflows/integration_test.yaml
     with:
diff --git a/.github/workflows/integration_test.yaml b/.github/workflows/integration_test.yaml
index b7d035f37..9b668a63a 100644
--- a/.github/workflows/integration_test.yaml
+++ b/.github/workflows/integration_test.yaml
@@ -42,7 +42,9 @@ jobs:
               _, runner, task, variant = job.split(":")
               # Example: "test_charm.py"
               task = task.removeprefix("tests/spread/")
-              if runner.endswith("-arm"):
+              if "s390x" in runner:
+                  architecture = "s390x"
+              elif runner.endswith("-arm"):
                   architecture = "arm64"
               else:
                   architecture = "amd64"
@@ -86,8 +88,9 @@ jobs:
     runs-on: ${{ matrix.job.runner }}
     timeout-minutes: 217  # Sum of steps `timeout-minutes` + 5
     steps:
-      - name: Free up disk space
+      - name: (GitHub hosted) Free up disk space
         timeout-minutes: 1
+        if: ${{ !contains(matrix.job.runner, 'self-hosted') }}
         run: |
           printf '\nDisk usage before cleanup\n'
           df --human-readable
@@ -95,6 +98,10 @@ jobs:
           rm -r /opt/hostedtoolcache/
           printf '\nDisk usage after cleanup\n'
           df --human-readable
+      - name: (IS hosted) Disk usage
+        timeout-minutes: 1
+        if: ${{ contains(matrix.job.runner, 'self-hosted') }}
+        run: df --human-readable
       - name: Checkout
         timeout-minutes: 3
         uses: actions/checkout@v4
diff --git a/concierge.yaml b/concierge.yaml
index 361973cb8..95ee838d4 100644
--- a/concierge.yaml
+++ b/concierge.yaml
@@ -4,7 +4,7 @@ juju:
 providers:
   microk8s:
     enable: true
-    bootstrap: true
+    bootstrap: false
     addons:
       - dns
       - hostpath-storage
diff --git a/spread.yaml b/spread.yaml
index 7cd6e1a52..ac72e8599 100644
--- a/spread.yaml
+++ b/spread.yaml
@@ -86,6 +86,7 @@ backends:
     # Manually pass specific environment variables
     environment:
       CI: '$(HOST: echo $CI)'
+      DOCKERHUB_MIRROR: '$(HOST: echo $DOCKERHUB_MIRROR)'
     systems:
       - ubuntu-24.04:
           username: runner
@@ -93,6 +94,21 @@ backends:
           username: runner
           variants:
             - -juju29
+      - self-hosted-linux-s390x-noble-edge:
+          username: ubuntu
+          environment:
+            # Several python packages (e.g. cryptography, bcrypt) do not have s390x builds on PyPI,
+            # so they must be built from source. pkg-config & rust toolchain needed
+            # (These packages are being built when installing poetry or integration test Python
+            # dependencies)
+            CONCIERGE_EXTRA_DEBS: pipx,pkg-config,rustup
+            # s390x only available on edge risk of microk8s snap
+            # IS-hosted GitHub runners do not work with the strictly confined microk8s snap:
+            # https://github.com/canonical/microk8s/issues/5082
+            # https://chat.canonical.com/canonical/pl/i6yydsx5ifrepp56khq5fq5dke
+            CONCIERGE_MICROK8S_CHANNEL: latest/edge
+          variants:
+            - -juju29
 
 suites:
   tests/spread/:
@@ -109,10 +125,42 @@ prepare: |
   snap refresh --hold
   chown -R root:root "$SPREAD_PATH"
   cd "$SPREAD_PATH"
-  snap install --classic concierge
+  # Install via snap after https://github.com/canonical/concierge/pull/81 released
+  go install github.com/canonical/concierge@latest
+  
+  if [[ -n "$DOCKERHUB_MIRROR" ]]
+  then
+    # Running on IS-hosted runner; configure microk8s to use Docker Hub mirror
+    # Run before concierge prepare because of https://github.com/canonical/concierge/issues/75
+
+    snap install microk8s --channel "$CONCIERGE_MICROK8S_CHANNEL" --classic
+  
+    # Wait for microk8s to populate iptables
+    # https://chat.canonical.com/canonical/pl/jo5cg6wqjjrudqd5ybj6hhttee
+    microk8s status --wait-ready
+
+    tee /var/snap/microk8s/current/args/certs.d/docker.io/hosts.toml << EOF
+    server = "$DOCKERHUB_MIRROR"
+    [host."${DOCKERHUB_MIRROR#'https://'}"]
+    capabilities = ["pull", "resolve"]
+  EOF
+    microk8s stop
+    microk8s start
+  fi
+
+  # Install charmcraft & pipx on lxd-vm backend and install pipx on IS-hosted runners
+  ~/go/bin/concierge prepare --trace
+
+  microk8s config | juju add-k8s my-k8s --client
+  juju bootstrap my-k8s concierge-microk8s
+  juju add-model testing
 
-  # Install charmcraft & pipx (on lxd-vm backend)
-  concierge prepare --trace
+  if [[ $SPREAD_SYSTEM == *"s390x"* ]]
+  then
+    rustup set profile minimal
+    # TODO add renovate comment for rust version
+    rustup default 1.88.0
+  fi
 
   pipx install tox poetry
 prepare-each: |
@@ -124,7 +172,7 @@ prepare-each: |
     poetry add --lock --group integration juju@^2
   fi
   # `concierge prepare` needs to be run for each spread job in case Juju version changed
-  concierge prepare --trace
+  ~/go/bin/concierge prepare --trace
 
   # Unable to set constraint on all models because of Juju bug:
   # https://bugs.launchpad.net/juju/+bug/2065050
diff --git a/tests/integration/markers.py b/tests/integration/markers.py
index 46d84271d..d38ea4a4c 100644
--- a/tests/integration/markers.py
+++ b/tests/integration/markers.py
@@ -15,3 +15,6 @@
 arm64_only = pytest.mark.skipif(
     architecture.architecture != "arm64", reason="Requires arm64 architecture"
 )
+s390x_only = pytest.mark.skipif(
+    architecture.architecture != "s390x", reason="Requires s390x architecture"
+)
diff --git a/tests/integration/test_architecture.py b/tests/integration/test_architecture.py
index b7044c8c5..b8dd06f70 100644
--- a/tests/integration/test_architecture.py
+++ b/tests/integration/test_architecture.py
@@ -61,4 +61,25 @@ async def test_amd_charm_on_arm_host(ops_test: OpsTest) -> None:
     )
 
 
-# TODO: add s390x test
+@markers.s390x_only
+async def test_amd_charm_on_s390x_host(ops_test: OpsTest) -> None:
+    """Tries deploying an amd64 charm on s390x host."""
+    charm = "./mysql-router-k8s_ubuntu@22.04-amd64.charm"
+
+    resources = {
+        "mysql-router-image": METADATA["resources"]["mysql-router-image"]["upstream-source"]
+    }
+
+    await ops_test.model.deploy(
+        charm,
+        application_name=MYSQL_ROUTER_APP_NAME,
+        num_units=1,
+        resources=resources,
+        base="ubuntu@22.04",
+    )
+
+    await ops_test.model.wait_for_idle(
+        apps=[MYSQL_ROUTER_APP_NAME],
+        status="error",
+        raise_on_error=False,
+    )
diff --git a/tests/integration/test_exporter_with_tls.py b/tests/integration/test_exporter_with_tls.py
index b872bb8c1..bbc7601e1 100644
--- a/tests/integration/test_exporter_with_tls.py
+++ b/tests/integration/test_exporter_with_tls.py
@@ -34,8 +34,8 @@
 
 if juju_.is_3_or_higher:
     tls_app_name = "self-signed-certificates"
-    if architecture.architecture == "arm64":
-        tls_channel = "latest/edge"
+    if architecture.architecture == "s390x":
+        tls_channel = "1/edge"
     else:
         tls_channel = "latest/stable"
     tls_config = {"ca-common-name": "Test CA"}
@@ -138,7 +138,6 @@ async def test_exporter_endpoint(ops_test: OpsTest, charm) -> None:
         application_name=tls_app_name,
         channel=tls_channel,
         config=tls_config,
-        base="ubuntu@22.04",
     )
 
     await ops_test.model.wait_for_idle([tls_app_name], status="active", timeout=SLOW_TIMEOUT)
diff --git a/tests/integration/test_expose_external.py b/tests/integration/test_expose_external.py
index 92f1348cc..32b2f93c4 100644
--- a/tests/integration/test_expose_external.py
+++ b/tests/integration/test_expose_external.py
@@ -36,8 +36,8 @@
 TLS_SETUP_SLEEP_TIME = 30
 if juju_.is_3_or_higher:
     TLS_APP_NAME = "self-signed-certificates"
-    if architecture.architecture == "arm64":
-        TLS_CHANNEL = "latest/edge"
+    if architecture.architecture == "s390x":
+        TLS_CHANNEL = "1/edge"
     else:
         TLS_CHANNEL = "latest/stable"
     TLS_CONFIG = {"ca-common-name": "Test CA"}
@@ -197,7 +197,6 @@ async def test_expose_external_with_tls(ops_test: OpsTest) -> None:
         TLS_APP_NAME,
         channel=TLS_CHANNEL,
         config=TLS_CONFIG,
-        base="ubuntu@22.04",
     )
     async with ops_test.fast_forward("60s"):
         await ops_test.model.wait_for_idle(
diff --git a/tests/integration/test_tls.py b/tests/integration/test_tls.py
index 00fb17f95..e21a434ba 100644
--- a/tests/integration/test_tls.py
+++ b/tests/integration/test_tls.py
@@ -30,8 +30,8 @@
 
 if juju_.is_3_or_higher:
     tls_app_name = "self-signed-certificates"
-    if architecture.architecture == "arm64":
-        tls_channel = "latest/edge"
+    if architecture.architecture == "s390x":
+        tls_channel = "1/edge"
     else:
         tls_channel = "latest/stable"
     tls_config = {"ca-common-name": "Test CA"}
@@ -79,7 +79,6 @@ async def test_deploy_and_relate(ops_test: OpsTest, charm) -> None:
                 application_name=tls_app_name,
                 channel=tls_channel,
                 config=tls_config,
-                base="ubuntu@22.04",
             ),
             ops_test.model.deploy(
                 TEST_APP_NAME,
diff --git a/tests/spread/test_architecture.py/task.yaml b/tests/spread/test_architecture.py/task.yaml
deleted file mode 100644
index cad863364..000000000
--- a/tests/spread/test_architecture.py/task.yaml
+++ /dev/null
@@ -1,9 +0,0 @@
-summary: test_architecture.py
-environment:
-  TEST_MODULE: test_architecture.py
-execute: |
-  tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
-artifacts:
-  - allure-results
-backends:
-  - -lxd-vm  # This task requires charm built on different architecture from host
diff --git a/tests/spread/test_charm.py/task.yaml b/tests/spread/test_charm.py/task.yaml
deleted file mode 100644
index 96450bdc3..000000000
--- a/tests/spread/test_charm.py/task.yaml
+++ /dev/null
@@ -1,7 +0,0 @@
-summary: test_charm.py
-environment:
-  TEST_MODULE: test_charm.py
-execute: |
-  tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
-artifacts:
-  - allure-results
diff --git a/tests/spread/test_exporter.py/task.yaml b/tests/spread/test_exporter.py/task.yaml
deleted file mode 100644
index 800f0c4a2..000000000
--- a/tests/spread/test_exporter.py/task.yaml
+++ /dev/null
@@ -1,9 +0,0 @@
-summary: test_exporter.py
-environment:
-  TEST_MODULE: test_exporter.py
-execute: |
-  tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
-artifacts:
-  - allure-results
-systems:
-  - -ubuntu-24.04-arm
diff --git a/tests/spread/test_exporter_with_tls.py/task.yaml b/tests/spread/test_exporter_with_tls.py/task.yaml
deleted file mode 100644
index 4d7dce7fc..000000000
--- a/tests/spread/test_exporter_with_tls.py/task.yaml
+++ /dev/null
@@ -1,9 +0,0 @@
-summary: test_exporter_with_tls.py
-environment:
-  TEST_MODULE: test_exporter_with_tls.py
-execute: |
-  tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
-artifacts:
-  - allure-results
-systems:
-  - -ubuntu-24.04-arm
diff --git a/tests/spread/test_log_rotation.py/task.yaml b/tests/spread/test_log_rotation.py/task.yaml
deleted file mode 100644
index 8e8900110..000000000
--- a/tests/spread/test_log_rotation.py/task.yaml
+++ /dev/null
@@ -1,7 +0,0 @@
-summary: test_log_rotation.py
-environment:
-  TEST_MODULE: test_log_rotation.py
-execute: |
-  tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
-artifacts:
-  - allure-results
diff --git a/tests/spread/test_upgrade.py/task.yaml b/tests/spread/test_upgrade.py/task.yaml
deleted file mode 100644
index a53e8a4ee..000000000
--- a/tests/spread/test_upgrade.py/task.yaml
+++ /dev/null
@@ -1,7 +0,0 @@
-summary: test_upgrade.py
-environment:
-  TEST_MODULE: test_upgrade.py
-execute: |
-  tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
-artifacts:
-  - allure-results