diff --git a/tests/system/test_lro.py b/tests/system/test_lro.py
index a30e738fe..c5bf76890 100644
--- a/tests/system/test_lro.py
+++ b/tests/system/test_lro.py
@@ -20,9 +20,6 @@
 
 
 def test_lro(echo):
-    if isinstance(echo.transport, type(echo).get_transport_class("rest")):
-        # (TODO: dovs) Temporarily disabling rest
-        return
 
     future = echo.wait({
         'end_time': datetime.now(tz=timezone.utc) + timedelta(seconds=1),
diff --git a/tests/system/test_mixins.py b/tests/system/test_mixins.py
new file mode 100644
index 000000000..fb35a0f15
--- /dev/null
+++ b/tests/system/test_mixins.py
@@ -0,0 +1,152 @@
+# Copyright 2024 Google LLC
+#
+# 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
+#
+#     https://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.
+
+import os
+import pytest
+
+from google.api_core import exceptions
+
+
+def test_get_operation(echo):
+    with pytest.raises(exceptions.NotFound):
+        echo.get_operation({"name": "operations/**"})
+
+
+def test_list_operations(echo):
+    response = echo.list_operations({"name": "operations/name"})
+    assert response.operations[0].name == "a/pending/thing"
+
+
+def test_delete_operation(echo):
+    echo.delete_operation({"name": "operations/name"})
+
+
+def test_cancel_operation(echo):
+    echo.cancel_operation({"name": "operations/name"})
+
+
+def test_set_iam_policy(echo):
+    policy = echo.set_iam_policy(
+        {"resource": "users/user", "policy": {"version": 20240919}}
+    )
+    assert policy.version == 20240919
+
+
+def test_get_iam_policy(echo):
+    # First we need to set a policy, before we can get it
+    echo.set_iam_policy({"resource": "users/user", "policy": {"version": 20240920}})
+    policy = echo.get_iam_policy(
+        {
+            "resource": "users/user",
+        }
+    )
+    assert policy.version == 20240920
+
+
+def test_test_iam_permissions(echo):
+    # First we need to set a policy, before we can call test_iam_permissions
+    echo.set_iam_policy({"resource": "users/user", "policy": {"version": 20240920}})
+    response = echo.test_iam_permissions(
+        {"resource": "users/user", "permissions": ["test_some_permission"]}
+    )
+    assert response.permissions == ["test_some_permission"]
+
+
+def test_get_location(echo):
+    response = echo.get_location(
+        {
+            "name": "projects/some_project/locations/some_location",
+        }
+    )
+    assert response.name == "projects/some_project/locations/some_location"
+
+
+def test_list_locations(echo):
+    response = echo.list_locations(
+        {
+            "name": "projects/some_project",
+        }
+    )
+    assert response.locations[0].name == "projects/some_project/locations/us-north"
+
+
+if os.environ.get("GAPIC_PYTHON_ASYNC", "true") == "true":
+
+    @pytest.mark.asyncio
+    async def test_get_operation_async(async_echo):
+        with pytest.raises(exceptions.NotFound):
+            await async_echo.get_operation({"name": "operations/**"})
+
+    @pytest.mark.asyncio
+    async def test_list_operations_async(async_echo):
+        response = await async_echo.list_operations({"name": "operations/name"})
+        assert response.operations[0].name == "a/pending/thing"
+
+    @pytest.mark.asyncio
+    async def test_delete_operation_async(async_echo):
+        await async_echo.delete_operation({"name": "operations/name"})
+
+    @pytest.mark.asyncio
+    async def test_cancel_operation_async(async_echo):
+        await async_echo.cancel_operation({"name": "operations/name"})
+
+    @pytest.mark.asyncio
+    async def test_set_iam_policy_async(async_echo):
+        policy = await async_echo.set_iam_policy(
+            {"resource": "users/user", "policy": {"version": 20240919}}
+        )
+        assert policy.version == 20240919
+
+    @pytest.mark.asyncio
+    async def test_get_iam_policy_async(async_echo):
+        # First we need to set a policy, before we can get it
+        await async_echo.set_iam_policy(
+            {"resource": "users/user", "policy": {"version": 20240920}}
+        )
+        policy = await async_echo.get_iam_policy(
+            {
+                "resource": "users/user",
+            }
+        )
+        policy.version == 20240920
+
+    @pytest.mark.asyncio
+    async def test_test_iam_permissions_async(async_echo):
+        # First we need to set a policy, before we can get it
+        await async_echo.set_iam_policy(
+            {"resource": "users/user", "policy": {"version": 20240920}}
+        )
+
+        response = await async_echo.test_iam_permissions(
+            {"resource": "users/user", "permissions": ["test_some_permission"]}
+        )
+        assert response.permissions == ["test_some_permission"]
+
+    @pytest.mark.asyncio
+    async def test_get_location_async(async_echo):
+        response = await async_echo.get_location(
+            {
+                "name": "projects/some_project/locations/some_location",
+            }
+        )
+        assert response.name == "projects/some_project/locations/some_location"
+
+    @pytest.mark.asyncio
+    async def test_list_locations_async(async_echo):
+        response = await async_echo.list_locations(
+            {
+                "name": "projects/some_project",
+            }
+        )
+        assert response.locations[0].name == "projects/some_project/locations/us-north"