diff --git a/.github/workflows/ci-code.yml b/.github/workflows/ci-code.yml
index a8d0cb9a08..57e85bb004 100644
--- a/.github/workflows/ci-code.yml
+++ b/.github/workflows/ci-code.yml
@@ -104,7 +104,7 @@ jobs:
         AIIDA_WARN_v3: 1
       # Python 3.12 has a performance regression when running with code coverage
       # so run code coverage only for python 3.9.
-      run: pytest --db-backend psql -m 'not nightly' tests/ ${{ matrix.python-version == '3.9' && '--cov aiida' || '' }}
+      run: pytest -n auto --db-backend psql -m 'not nightly' tests/ ${{ matrix.python-version == '3.9' && '--cov aiida' || '' }}
 
     - name: Upload coverage report
       if: matrix.python-version == 3.9 && github.repository == 'aiidateam/aiida-core'
@@ -139,7 +139,7 @@ jobs:
     - name: Run test suite
       env:
         AIIDA_WARN_v3: 0
-      run: pytest -m 'presto' tests/
+      run: pytest -n auto -m 'presto' tests/
 
 
   verdi:
diff --git a/.github/workflows/test-install.yml b/.github/workflows/test-install.yml
index d315a50691..3abeb4a2ba 100644
--- a/.github/workflows/test-install.yml
+++ b/.github/workflows/test-install.yml
@@ -229,7 +229,7 @@ jobs:
       env:
         AIIDA_TEST_PROFILE: test_aiida
         AIIDA_WARN_v3: 1
-      run: pytest --db-backend psql tests -m 'not nightly' tests/
+      run: pytest -n auto --db-backend psql tests -m 'not nightly' tests/
 
     - name: Freeze test environment
       run: pip freeze | sed '1d' | tee requirements-py-${{ matrix.python-version }}.txt
diff --git a/pyproject.toml b/pyproject.toml
index 35f2f23b7f..7641b7ed72 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -241,6 +241,7 @@ tests = [
   'pytest-rerunfailures~=12.0',
   'pytest-benchmark~=4.0',
   'pytest-regressions~=2.2',
+  'pytest-xdist~=3.6',
   'pympler~=1.0',
   'coverage~=7.0',
   'sphinx~=7.2.0',
diff --git a/requirements/requirements-py-3.10.txt b/requirements/requirements-py-3.10.txt
index b2408e8087..23e3b24c45 100644
--- a/requirements/requirements-py-3.10.txt
+++ b/requirements/requirements-py-3.10.txt
@@ -149,6 +149,7 @@ pytest-datadir==1.4.1
 pytest-regressions==2.4.2
 pytest-rerunfailures==12.0
 pytest-timeout==2.2.0
+pytest-xdist==3.6.1
 python-dateutil==2.8.2
 python-json-logger==2.0.7
 python-memcached==1.59
diff --git a/requirements/requirements-py-3.11.txt b/requirements/requirements-py-3.11.txt
index 24acc25a6b..a0f1aa7a75 100644
--- a/requirements/requirements-py-3.11.txt
+++ b/requirements/requirements-py-3.11.txt
@@ -148,6 +148,7 @@ pytest-datadir==1.4.1
 pytest-regressions==2.4.2
 pytest-rerunfailures==12.0
 pytest-timeout==2.2.0
+pytest-xdist==3.6.1
 python-dateutil==2.8.2
 python-json-logger==2.0.7
 python-memcached==1.59
diff --git a/requirements/requirements-py-3.12.txt b/requirements/requirements-py-3.12.txt
index 3f5d72ebb6..8047763fea 100644
--- a/requirements/requirements-py-3.12.txt
+++ b/requirements/requirements-py-3.12.txt
@@ -148,6 +148,7 @@ pytest-datadir==1.5.0
 pytest-regressions==2.5.0
 pytest-rerunfailures==12.0
 pytest-timeout==2.2.0
+pytest-xdist==3.6.1
 python-dateutil==2.8.2
 python-json-logger==2.0.7
 python-memcached==1.59
diff --git a/requirements/requirements-py-3.9.txt b/requirements/requirements-py-3.9.txt
index 3087e62844..7f6c5bbc6f 100644
--- a/requirements/requirements-py-3.9.txt
+++ b/requirements/requirements-py-3.9.txt
@@ -151,6 +151,7 @@ pytest-datadir==1.4.1
 pytest-regressions==2.4.2
 pytest-rerunfailures==12.0
 pytest-timeout==2.2.0
+pytest-xdist==3.6.1
 python-dateutil==2.8.2
 python-json-logger==2.0.7
 python-memcached==1.59
diff --git a/tests/orm/test_querybuilder.py b/tests/orm/test_querybuilder.py
index c434c93411..6d5d7cefc4 100644
--- a/tests/orm/test_querybuilder.py
+++ b/tests/orm/test_querybuilder.py
@@ -372,6 +372,7 @@ def test_dict_multiple_projections(self):
         assert dictionary['*'].pk == node.pk
         assert dictionary['id'] == node.pk
 
+    @pytest.mark.usefixtures('aiida_profile_clean')
     def test_operators_eq_lt_gt(self):
         nodes = [orm.Data() for _ in range(8)]
 
@@ -394,6 +395,7 @@ def test_operators_eq_lt_gt(self):
         assert orm.QueryBuilder().append(orm.Node, filters={'attributes.fa': {'>': 1.02}}).count() == 4
         assert orm.QueryBuilder().append(orm.Node, filters={'attributes.fa': {'>=': 1.02}}).count() == 5
 
+    @pytest.mark.usefixtures('aiida_profile_clean')
     def test_subclassing(self):
         s = orm.StructureData()
         s.base.attributes.set('cat', 'miau')
@@ -514,6 +516,7 @@ def test_append_validation(self):
         # So this should work now:
         qb.append(orm.StructureData, tag='s').limit(2).dict()
 
+    @pytest.mark.usefixtures('aiida_profile_clean')
     def test_tuples(self):
         """Test appending ``cls`` tuples."""
         orm.Group(label='helloworld').store()
@@ -696,6 +699,7 @@ def test_query_links(self):
 class TestMultipleProjections:
     """Unit tests for the QueryBuilder ORM class."""
 
+    @pytest.mark.usefixtures('aiida_profile_clean')
     def test_first_multiple_projections(self):
         """Test `first()` returns correct types and numbers for multiple projections."""
         orm.Data().store()
diff --git a/tests/restapi/conftest.py b/tests/restapi/conftest.py
index 8abe8f9296..442814a808 100644
--- a/tests/restapi/conftest.py
+++ b/tests/restapi/conftest.py
@@ -8,18 +8,27 @@
 ###########################################################################
 """pytest fixtures for use with the aiida.restapi tests"""
 
+from typing import Optional
+
 import pytest
 
 
 @pytest.fixture(scope='function')
 def restapi_server():
     """Make REST API server"""
+    import socket
+
     from werkzeug.serving import make_server
 
     from aiida.restapi.common.config import CLI_DEFAULTS
     from aiida.restapi.run_api import configure_api
 
     def _restapi_server(restapi=None):
+        # Dynamically find a free port
+        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
+            sock.bind(('', 0))  # Bind to a free port provided by the OS
+            _, port = sock.getsockname()  # Get the dynamically assigned port
+
         if restapi is None:
             flask_restapi = configure_api()
         else:
@@ -27,7 +36,7 @@ def _restapi_server(restapi=None):
 
         return make_server(
             host=CLI_DEFAULTS['HOST_NAME'],
-            port=int(CLI_DEFAULTS['PORT']),
+            port=port,
             app=flask_restapi.app,
             threaded=True,
             processes=1,
@@ -44,7 +53,10 @@ def _restapi_server(restapi=None):
 def server_url():
     from aiida.restapi.common.config import API_CONFIG, CLI_DEFAULTS
 
-    return f"http://{CLI_DEFAULTS['HOST_NAME']}:{CLI_DEFAULTS['PORT']}{API_CONFIG['PREFIX']}"
+    def _server_url(hostname: Optional[str] = None, port: Optional[int] = None):
+        return f"http://{hostname or CLI_DEFAULTS['HOST_NAME']}:{port or CLI_DEFAULTS['PORT']}{API_CONFIG['PREFIX']}"
+
+    return _server_url
 
 
 @pytest.fixture
diff --git a/tests/restapi/test_identifiers.py b/tests/restapi/test_identifiers.py
index 8e3f245f6b..0c593e433e 100644
--- a/tests/restapi/test_identifiers.py
+++ b/tests/restapi/test_identifiers.py
@@ -105,9 +105,11 @@ def test_full_type_unregistered(process_class, restapi_server, server_url):
     server = restapi_server()
     server_thread = Thread(target=server.serve_forever)
 
+    _server_url = server_url(port=server.server_port)
+
     try:
         server_thread.start()
-        type_count_response = requests.get(f'{server_url}/nodes/full_types', timeout=10)
+        type_count_response = requests.get(f'{_server_url}/nodes/full_types', timeout=10)
     finally:
         server.shutdown()
 
@@ -189,9 +191,11 @@ def test_full_type_backwards_compatibility(node_class, restapi_server, server_ur
     server = restapi_server()
     server_thread = Thread(target=server.serve_forever)
 
+    _server_url = server_url(port=server.server_port)
+
     try:
         server_thread.start()
-        type_count_response = requests.get(f'{server_url}/nodes/full_types', timeout=10)
+        type_count_response = requests.get(f'{_server_url}/nodes/full_types', timeout=10)
     finally:
         server.shutdown()
 
diff --git a/tests/restapi/test_statistics.py b/tests/restapi/test_statistics.py
index e059de70ac..f125ccff1d 100644
--- a/tests/restapi/test_statistics.py
+++ b/tests/restapi/test_statistics.py
@@ -42,10 +42,12 @@ def test_count_consistency(restapi_server, server_url):
     server = restapi_server()
     server_thread = Thread(target=server.serve_forever)
 
+    _server_url = server_url(port=server.server_port)
+
     try:
         server_thread.start()
-        type_count_response = requests.get(f'{server_url}/nodes/full_types_count', timeout=10)
-        statistics_response = requests.get(f'{server_url}/nodes/statistics', timeout=10)
+        type_count_response = requests.get(f'{_server_url}/nodes/full_types_count', timeout=10)
+        statistics_response = requests.get(f'{_server_url}/nodes/statistics', timeout=10)
     finally:
         server.shutdown()
 
diff --git a/tests/restapi/test_threaded_restapi.py b/tests/restapi/test_threaded_restapi.py
index bad1a8a76f..40a994776b 100644
--- a/tests/restapi/test_threaded_restapi.py
+++ b/tests/restapi/test_threaded_restapi.py
@@ -36,17 +36,19 @@ def test_run_threaded_server(restapi_server, server_url, aiida_localhost):
     This test will fail, if database connections are not being properly closed by the end-point calls.
     """
     server = restapi_server()
-    computer_id = aiida_localhost.uuid
 
     # Create a thread that will contain the running server,
     # since we do not wish to block the main thread
     server_thread = Thread(target=server.serve_forever)
+    _server_url = server_url(port=server.server_port)
+
+    computer_id = aiida_localhost.uuid
 
     try:
         server_thread.start()
 
         for _ in range(NO_OF_REQUESTS):
-            response = requests.get(f'{server_url}/computers/{computer_id}', timeout=10)
+            response = requests.get(f'{_server_url}/computers/{computer_id}', timeout=10)
 
             assert response.status_code == 200
 
diff --git a/tests/tools/archive/orm/test_authinfo.py b/tests/tools/archive/orm/test_authinfo.py
index 650724a514..e2bb653cbb 100644
--- a/tests/tools/archive/orm/test_authinfo.py
+++ b/tests/tools/archive/orm/test_authinfo.py
@@ -16,6 +16,7 @@
 
 
 @pytest.mark.usefixtures('aiida_localhost')
+@pytest.mark.usefixtures('aiida_profile_clean')
 def test_create_all_no_authinfo(tmp_path):
     """Test archive creation that does not include authinfo."""
     filename1 = tmp_path / 'export1.aiida'
@@ -25,6 +26,7 @@ def test_create_all_no_authinfo(tmp_path):
 
 
 @pytest.mark.usefixtures('aiida_localhost')
+@pytest.mark.usefixtures('aiida_profile_clean')
 def test_create_all_with_authinfo(tmp_path):
     """Test archive creation that does include authinfo."""
     filename1 = tmp_path / 'export1.aiida'
@@ -33,6 +35,7 @@ def test_create_all_with_authinfo(tmp_path):
         assert archive.querybuilder().append(orm.AuthInfo).count() == 1
 
 
+@pytest.mark.usefixtures('aiida_profile_clean')
 def test_create_comp_with_authinfo(tmp_path, aiida_localhost):
     """Test archive creation that does include authinfo."""
     filename1 = tmp_path / 'export1.aiida'
@@ -41,6 +44,7 @@ def test_create_comp_with_authinfo(tmp_path, aiida_localhost):
         assert archive.querybuilder().append(orm.AuthInfo).count() == 1
 
 
+@pytest.mark.usefixtures('aiida_profile_clean')
 def test_import_authinfo(aiida_profile, tmp_path, aiida_localhost):
     """Test archive import, including authinfo"""
     filename1 = tmp_path / 'export1.aiida'
diff --git a/tests/tools/archive/orm/test_groups.py b/tests/tools/archive/orm/test_groups.py
index e40e1ba4be..556d1617b3 100644
--- a/tests/tools/archive/orm/test_groups.py
+++ b/tests/tools/archive/orm/test_groups.py
@@ -18,7 +18,7 @@
 from aiida.tools.archive import create_archive, import_archive
 
 
-def test_nodes_in_group(aiida_profile, tmp_path, aiida_localhost):
+def test_nodes_in_group(aiida_profile_clean, tmp_path, aiida_localhost):
     """This test checks that nodes that belong to a specific group are
     correctly imported and exported.
     """
@@ -52,7 +52,7 @@ def test_nodes_in_group(aiida_profile, tmp_path, aiida_localhost):
     filename1 = tmp_path / 'export1.aiida'
     create_archive([sd1, jc1, gr1], filename=filename1)
     n_uuids = [sd1.uuid, jc1.uuid]
-    aiida_profile.reset_storage()
+    aiida_profile_clean.reset_storage()
     import_archive(filename1)
 
     # Check that the imported nodes are correctly imported and that
@@ -66,7 +66,7 @@ def test_nodes_in_group(aiida_profile, tmp_path, aiida_localhost):
     assert builder.count() == 1, 'The group was not found.'
 
 
-def test_group_export(tmp_path, aiida_profile):
+def test_group_export(tmp_path, aiida_profile_clean):
     """Exporting a group includes its extras and nodes."""
     # Create a new user
     new_email = uuid.uuid4().hex
@@ -90,7 +90,7 @@ def test_group_export(tmp_path, aiida_profile):
     filename = tmp_path / 'export.aiida'
     create_archive([group], filename=filename)
     n_uuids = [sd1.uuid]
-    aiida_profile.reset_storage()
+    aiida_profile_clean.reset_storage()
     import_archive(filename)
 
     # Check that the imported nodes are correctly imported and that
@@ -106,7 +106,7 @@ def test_group_export(tmp_path, aiida_profile):
     assert imported_group.base.extras.get('test') == 1, 'Extra missing on imported group'
 
 
-def test_group_import_existing(tmp_path, aiida_profile):
+def test_group_import_existing(tmp_path, aiida_profile_clean):
     """Testing what happens when I try to import a group that already exists in the
     database. This should raise an appropriate exception
     """
@@ -131,7 +131,7 @@ def test_group_import_existing(tmp_path, aiida_profile):
     # At this point we export the generated data
     filename = tmp_path / 'export1.aiida'
     create_archive([group], filename=filename)
-    aiida_profile.reset_storage()
+    aiida_profile_clean.reset_storage()
 
     # Creating a group of the same name
     group = orm.Group(label='node_group_existing')
@@ -155,7 +155,7 @@ def test_group_import_existing(tmp_path, aiida_profile):
     assert builder.count() == 2
 
 
-def test_import_to_group(tmp_path, aiida_profile):
+def test_import_to_group(tmp_path, aiida_profile_clean):
     """Test `group` parameter
     Make sure an unstored Group is stored by the import function, forwarding the Group object.
     Make sure the Group is correctly handled and used for imported nodes.
@@ -168,7 +168,7 @@ def test_import_to_group(tmp_path, aiida_profile):
     # Export Nodes
     filename = tmp_path / 'export.aiida'
     create_archive([data1, data2], filename=filename)
-    aiida_profile.reset_storage()
+    aiida_profile_clean.reset_storage()
 
     # Create Group, do not store
     group_label = 'import_madness'
diff --git a/tests/tools/archive/orm/test_logs.py b/tests/tools/archive/orm/test_logs.py
index a6c80edb6b..b355ca8ddb 100644
--- a/tests/tools/archive/orm/test_logs.py
+++ b/tests/tools/archive/orm/test_logs.py
@@ -12,7 +12,7 @@
 from aiida.tools.archive import create_archive, import_archive
 
 
-def test_critical_log_msg_and_metadata(tmp_path, aiida_profile):
+def test_critical_log_msg_and_metadata(tmp_path, aiida_profile_clean):
     """Testing logging of critical message"""
     message = 'Testing logging of critical failure'
     calc = orm.CalculationNode()
@@ -33,7 +33,7 @@ def test_critical_log_msg_and_metadata(tmp_path, aiida_profile):
     export_file = tmp_path.joinpath('export.aiida')
     create_archive([calc], filename=export_file)
 
-    aiida_profile.reset_storage()
+    aiida_profile_clean.reset_storage()
 
     import_archive(export_file)
 
@@ -45,7 +45,7 @@ def test_critical_log_msg_and_metadata(tmp_path, aiida_profile):
     assert logs[0].metadata == log_metadata
 
 
-def test_exclude_logs_flag(tmp_path, aiida_profile):
+def test_exclude_logs_flag(tmp_path, aiida_profile_clean):
     """Test that the `include_logs` argument for `export` works."""
     log_msg = 'Testing logging of critical failure'
 
@@ -65,7 +65,7 @@ def test_exclude_logs_flag(tmp_path, aiida_profile):
     create_archive([calc], filename=export_file, include_logs=False)
 
     # Clean database and reimport exported data
-    aiida_profile.reset_storage()
+    aiida_profile_clean.reset_storage()
     import_archive(export_file)
 
     # Finding all the log messages
@@ -80,7 +80,7 @@ def test_exclude_logs_flag(tmp_path, aiida_profile):
     assert str(import_calcs[0][0]) == calc_uuid
 
 
-def test_export_of_imported_logs(tmp_path, aiida_profile):
+def test_export_of_imported_logs(tmp_path, aiida_profile_clean):
     """Test export of imported Log"""
     log_msg = 'Testing export of imported log'
 
@@ -102,7 +102,7 @@ def test_export_of_imported_logs(tmp_path, aiida_profile):
     create_archive([calc], filename=export_file)
 
     # Clean database and reimport exported data
-    aiida_profile.reset_storage()
+    aiida_profile_clean.reset_storage()
     import_archive(export_file)
 
     # Finding all the log messages
@@ -123,7 +123,7 @@ def test_export_of_imported_logs(tmp_path, aiida_profile):
     create_archive([calc], filename=re_export_file)
 
     # Clean database and reimport exported data
-    aiida_profile.reset_storage()
+    aiida_profile_clean.reset_storage()
     import_archive(re_export_file)
 
     # Finding all the log messages
diff --git a/tests/tools/archive/test_simple.py b/tests/tools/archive/test_simple.py
index 2f7377eb22..ac6209ab95 100644
--- a/tests/tools/archive/test_simple.py
+++ b/tests/tools/archive/test_simple.py
@@ -21,7 +21,7 @@
 
 
 @pytest.mark.parametrize('entities', ['all', 'specific'])
-def test_base_data_nodes(aiida_profile, tmp_path, entities):
+def test_base_data_nodes(aiida_profile_clean, tmp_path, entities):
     """Test ex-/import of Base Data nodes"""
     # producing values for each base type
     values = ('Hello', 6, -1.2399834e12, False)
@@ -46,7 +46,7 @@ def test_base_data_nodes(aiida_profile, tmp_path, entities):
     # actually export now
     create(filename=filename)
     # cleaning:
-    aiida_profile.reset_storage()
+    aiida_profile_clean.reset_storage()
     # Importing back the data:
     import_archive(filename)
     # Checking whether values are preserved:
diff --git a/tests/tools/groups/test_paths.py b/tests/tools/groups/test_paths.py
index 1cad363d46..6ff2459650 100644
--- a/tests/tools/groups/test_paths.py
+++ b/tests/tools/groups/test_paths.py
@@ -125,6 +125,7 @@ def test_walk_with_invalid_path():
     assert [c.path for c in sorted(group_path.walk())] == expected
 
 
+@pytest.mark.usefixtures('aiida_profile_clean')
 def test_walk_nodes():
     """Test the ``GroupPath.walk_nodes()`` function."""
     group, _ = orm.Group.collection.get_or_create('a')
diff --git a/tests/tools/visualization/test_graph.py b/tests/tools/visualization/test_graph.py
index db082017a9..276c000044 100644
--- a/tests/tools/visualization/test_graph.py
+++ b/tests/tools/visualization/test_graph.py
@@ -354,6 +354,7 @@ def test_graph_node_identifiers(self, node_id_type, monkeypatch, file_regression
         # The order of certain output lines can be randomly ordered so we split the file in lines, sort, and then join
         # them into a single string again. The node identifiers generated by the engine are of the form ``N{pk}`` and
         # they also clearly vary, so they are replaced with the ``NODE`` placeholder.
-        string = '\n'.join(sorted(graph.graphviz.source.strip().split('\n')))
+        string = graph.graphviz.source
         string = re.sub(r'N\d+', 'NODE', string)
+        string = '\n'.join(sorted(string.strip().split('\n')))
         file_regression.check(string)