diff --git a/packages/google-cloud-firestore/noxfile.py b/packages/google-cloud-firestore/noxfile.py
index 80fe70fa5798..ef340c48888a 100644
--- a/packages/google-cloud-firestore/noxfile.py
+++ b/packages/google-cloud-firestore/noxfile.py
@@ -82,7 +82,6 @@
     "pytest-asyncio==0.21.2",
     "six",
     "pyyaml",
-    "pytest-xdist",
 ]
 SYSTEM_TEST_LOCAL_DEPENDENCIES: List[str] = []
 SYSTEM_TEST_DEPENDENCIES: List[str] = []
@@ -403,8 +402,6 @@ def system(session):
     if system_test_exists:
         session.run(
             "py.test",
-            "-n",
-            "auto",
             "--quiet",
             f"--junitxml=system_{session.python}_sponge_log.xml",
             system_test_path,
@@ -413,8 +410,6 @@ def system(session):
     if system_test_folder_exists:
         session.run(
             "py.test",
-            "-n",
-            "auto",
             "--quiet",
             f"--junitxml=system_{session.python}_sponge_log.xml",
             system_test_folder_path,
diff --git a/packages/google-cloud-firestore/tests/system/test__helpers.py b/packages/google-cloud-firestore/tests/system/test__helpers.py
index 228bd0e4362a..83dd476602f2 100644
--- a/packages/google-cloud-firestore/tests/system/test__helpers.py
+++ b/packages/google-cloud-firestore/tests/system/test__helpers.py
@@ -16,7 +16,7 @@
 MISSING_DOCUMENT = "No document to update: "
 DOCUMENT_EXISTS = "Document already exists: "
 ENTERPRISE_MODE_ERROR = "only allowed on ENTERPRISE mode"
-UNIQUE_RESOURCE_ID = unique_resource_id("-") + "-" + str(os.getpid())
+UNIQUE_RESOURCE_ID = unique_resource_id("-")
 EMULATOR_CREDS = EmulatorCreds()
 FIRESTORE_EMULATOR = os.environ.get(_FIRESTORE_EMULATOR_HOST) is not None
 FIRESTORE_OTHER_DB = os.environ.get("SYSTEM_TESTS_DATABASE", "system-tests-named-db")
diff --git a/packages/google-cloud-firestore/tests/system/test_system.py b/packages/google-cloud-firestore/tests/system/test_system.py
index fe475206d37f..bcdc96c10f63 100644
--- a/packages/google-cloud-firestore/tests/system/test_system.py
+++ b/packages/google-cloud-firestore/tests/system/test_system.py
@@ -2336,11 +2336,7 @@ def test_watch_document(client, cleanup, database):
     doc_ref.set({"first": "Jane", "last": "Doe", "born": 1900})
     cleanup(doc_ref.delete)
 
-    # TODO(https://github.com/googleapis/google-cloud-python/issues/17428):
-    # Investigate why these sleep/polling delays are needed for listener tests.
-    # Having arbitrary delays is fragile and can lead to flakiness.
-    # Explore event-driven synchronization.
-    sleep(0.2)
+    sleep(1)
 
     # Setup listener
     def on_snapshot(docs, changes, read_time):
@@ -2353,12 +2349,12 @@ def on_snapshot(docs, changes, read_time):
     # Alter document
     doc_ref.set({"first": "Ada", "last": "Lovelace", "born": 1815})
 
-    sleep(0.2)
+    sleep(1)
 
-    for _ in range(50):
+    for _ in range(10):
         if on_snapshot.called_count > 0:
             break
-        sleep(0.2)
+        sleep(1)
 
     if on_snapshot.called_count not in (1, 2):
         raise AssertionError(
@@ -2388,19 +2384,15 @@ def on_snapshot(docs, changes, read_time):
 
     collection_ref.on_snapshot(on_snapshot)
 
-    # TODO(https://github.com/googleapis/google-cloud-python/issues/17428):
-    # Investigate why these sleep/polling delays are needed for listener tests.
-    # Having arbitrary delays is fragile and can lead to flakiness.
-    # Explore event-driven synchronization.
     # delay here so initial on_snapshot occurs and isn't combined with set
-    sleep(0.2)
+    sleep(1)
 
     doc_ref.set({"first": "Ada", "last": "Lovelace", "born": 1815})
 
-    for _ in range(50):
+    for _ in range(10):
         if on_snapshot.born == 1815:
             break
-        sleep(0.2)
+        sleep(1)
 
     if on_snapshot.born != 1815:
         raise AssertionError(
@@ -2419,11 +2411,7 @@ def test_watch_query(client, cleanup, database):
     doc_ref.set({"first": "Jane", "last": "Doe", "born": 1900})
     cleanup(doc_ref.delete)
 
-    # TODO(https://github.com/googleapis/google-cloud-python/issues/17428):
-    # Investigate why these sleep/polling delays are needed for listener tests.
-    # Having arbitrary delays is fragile and can lead to flakiness.
-    # Explore event-driven synchronization.
-    sleep(0.2)
+    sleep(1)
 
     # Setup listener
     def on_snapshot(docs, changes, read_time):
@@ -2441,10 +2429,10 @@ def on_snapshot(docs, changes, read_time):
     # Alter document
     doc_ref.set({"first": "Ada", "last": "Lovelace", "born": 1815})
 
-    for _ in range(50):
+    for _ in range(10):
         if on_snapshot.called_count == 1:
             return
-        sleep(0.2)
+        sleep(1)
 
     if on_snapshot.called_count != 1:
         raise AssertionError(
@@ -2818,11 +2806,7 @@ def on_snapshot(docs, changes, read_time):
     on_snapshot.failed = None
     query_ref.on_snapshot(on_snapshot)
 
-    # TODO(https://github.com/googleapis/google-cloud-python/issues/17428):
-    # Investigate why these sleep/polling delays are needed for listener tests.
-    # Having arbitrary delays is fragile and can lead to flakiness.
-    # Explore event-driven synchronization.
-    sleep(0.2)
+    sleep(1)
 
     doc_ref1.set({"first": "Ada", "last": "Lovelace", "born": 1815})
     cleanup(doc_ref1.delete)
@@ -2839,10 +2823,10 @@ def on_snapshot(docs, changes, read_time):
     doc_ref5.set({"first": "Ada", "last": "lovelace", "born": 1815})
     cleanup(doc_ref5.delete)
 
-    for _ in range(50):
+    for _ in range(10):
         if on_snapshot.last_doc_count == 5:
             break
-        sleep(0.2)
+        sleep(1)
 
     if on_snapshot.failed:
         raise on_snapshot.failed