diff --git a/tests/integration/test_debug.py b/tests/integration/test_debug.py
index e699db36d6b..c27481c23ab 100644
--- a/tests/integration/test_debug.py
+++ b/tests/integration/test_debug.py
@@ -1,10 +1,8 @@
-from datetime import datetime
 import json
 import logging
 import os
 import re
 import subprocess
-import sys
 from typing import List
 from typing import Optional
 
@@ -36,7 +34,14 @@ def __eq__(self, other):
     return Match()
 
 
+@pytest.mark.subprocess()
 def test_standard_tags():
+    from datetime import datetime
+    import sys
+
+    import ddtrace
+    from ddtrace.internal import debug
+
     f = debug.collect(ddtrace.tracer)
 
     date = f.get("date")
@@ -94,7 +99,7 @@ def test_standard_tags():
     assert f.get("tracer_enabled") is True
     assert f.get("sampler_type") == "DatadogSampler"
     assert f.get("priority_sampler_type") == "N/A"
-    assert f.get("service") == "tests.integration"
+    assert f.get("service") == "ddtrace_subprocess_dir"
     assert f.get("dd_version") == ""
     assert f.get("debug") is False
     assert f.get("enabled_cli") is False
@@ -110,8 +115,13 @@ def test_standard_tags():
     assert icfg["flask"] == "N/A"
 
 
+@pytest.mark.subprocess()
 def test_debug_post_configure():
-    tracer = ddtrace.Tracer()
+    import re
+
+    from ddtrace import tracer
+    from ddtrace.internal import debug
+
     tracer.configure(
         hostname="0.0.0.0",
         port=1234,
@@ -122,16 +132,21 @@ def test_debug_post_configure():
     agent_url = f.get("agent_url")
     assert agent_url == "http://0.0.0.0:1234"
 
-    assert f.get("is_global_tracer") is False
+    assert f.get("is_global_tracer") is True
     assert f.get("tracer_enabled") is True
 
     agent_error = f.get("agent_error")
     # Error code can differ between Python version
     assert re.match("^Agent not reachable.*Connection refused", agent_error)
 
-    # Tracer doesn't support re-configure()-ing with a UDS after an initial
-    # configure with normal http settings. So we need a new tracer instance.
-    tracer = ddtrace.Tracer()
+
+@pytest.mark.subprocess()
+def test_debug_post_configure_uds():
+    import re
+
+    from ddtrace import tracer
+    from ddtrace.internal import debug
+
     tracer.configure(uds_path="/file.sock")
 
     f = debug.collect(tracer)
diff --git a/tests/integration/test_sampling.py b/tests/integration/test_sampling.py
index 902b430bbc8..707999b74b1 100644
--- a/tests/integration/test_sampling.py
+++ b/tests/integration/test_sampling.py
@@ -19,6 +19,9 @@
 
 def snapshot_parametrized_with_writers(f):
     def _patch(writer, tracer):
+        old_sampler = tracer._sampler
+        old_writer = tracer._writer
+        old_tags = tracer._tags
         if writer == "sync":
             writer = AgentWriter(
                 tracer.agent_trace_url,
@@ -29,11 +32,13 @@ def _patch(writer, tracer):
             writer._headers = tracer._writer._headers
         else:
             writer = tracer._writer
-        tracer.configure(writer=writer)
         try:
             return f(writer, tracer)
         finally:
-            tracer.shutdown()
+            tracer.flush()
+            # Reset tracer configurations to avoid leaking state between tests
+            tracer.configure(sampler=old_sampler, writer=old_writer)
+            tracer._tags = old_tags
 
     wrapped = snapshot(include_tracer=True, token_override=f.__name__)(_patch)
     return pytest.mark.parametrize(
diff --git a/tests/integration/test_trace_stats.py b/tests/integration/test_trace_stats.py
index 0fd7695fc23..e4ffde3d81b 100644
--- a/tests/integration/test_trace_stats.py
+++ b/tests/integration/test_trace_stats.py
@@ -5,12 +5,12 @@
 import mock
 import pytest
 
-from ddtrace import Tracer
 from ddtrace.constants import SPAN_MEASURED_KEY
 from ddtrace.ext import http
 from ddtrace.internal.processor.stats import SpanStatsProcessorV06
 from ddtrace.sampler import DatadogSampler
 from ddtrace.sampler import SamplingRule
+from tests.utils import DummyTracer
 from tests.utils import override_global_config
 
 from .test_integration import AGENT_VERSION
@@ -21,9 +21,8 @@
 
 @pytest.fixture
 def stats_tracer():
-    # type: (float) -> Generator[Tracer, None, None]
     with override_global_config(dict(_trace_compute_stats=True)):
-        tracer = Tracer()
+        tracer = DummyTracer()
         yield tracer
         tracer.shutdown()
 
@@ -70,7 +69,7 @@ def test_compute_stats_default_and_configure(run_python_code_in_subprocess, envv
     """Ensure stats computation can be enabled."""
 
     # Test enabling via `configure`
-    t = Tracer()
+    t = DummyTracer()
     assert not t._compute_stats
     assert not any(isinstance(p, SpanStatsProcessorV06) for p in t._span_processors)
     t.configure(compute_stats_enabled=True)
@@ -100,14 +99,16 @@ def test_compute_stats_default_and_configure(run_python_code_in_subprocess, envv
     assert status == 0, out + err
 
 
-def test_apm_opt_out_compute_stats_and_configure(run_python_code_in_subprocess):
+@pytest.mark.subprocess(err=b"WARNING:root:IAST not enabled but native module is being loaded\n")
+def test_apm_opt_out_compute_stats_and_configure():
     """
     Ensure stats computation is disabled, but reported as enabled,
     if APM is opt-out.
     """
+    from ddtrace import tracer as t
+    from ddtrace.internal.processor.stats import SpanStatsProcessorV06
 
     # Test via `configure`
-    t = Tracer()
     assert not t._compute_stats
     assert not any(isinstance(p, SpanStatsProcessorV06) for p in t._span_processors)
     t.configure(appsec_enabled=True, appsec_standalone_enabled=True)
@@ -116,8 +117,9 @@ def test_apm_opt_out_compute_stats_and_configure(run_python_code_in_subprocess):
     assert not t._compute_stats
     # but it's reported as enabled
     assert t._writer._headers.get("Datadog-Client-Computed-Stats") == "yes"
-    t.configure(appsec_enabled=False, appsec_standalone_enabled=False)
 
+
+def test_apm_opt_out_compute_stats_and_configure_env(run_python_code_in_subprocess):
     # Test via environment variable
     env = os.environ.copy()
     env.update({"DD_EXPERIMENTAL_APPSEC_STANDALONE_ENABLED": "true", "DD_APPSEC_ENABLED": "true"})
diff --git a/tests/profiling/test_profiler.py b/tests/profiling/test_profiler.py
index 7f98bbf6aa8..879a50afd54 100644
--- a/tests/profiling/test_profiler.py
+++ b/tests/profiling/test_profiler.py
@@ -232,36 +232,66 @@ def _check_url(prof, url, api_key, endpoint_path="profiling/v1/input"):
         pytest.fail("Unable to find HTTP exporter")
 
 
+@pytest.mark.subprocess()
 def test_tracer_url():
-    t = ddtrace.Tracer()
+    import os
+
+    from ddtrace import tracer as t
+    from ddtrace.profiling import profiler
+    from tests.profiling.test_profiler import _check_url
+
     t.configure(hostname="foobar")
     prof = profiler.Profiler(tracer=t)
     _check_url(prof, "http://foobar:8126", os.environ.get("DD_API_KEY"))
 
 
+@pytest.mark.subprocess()
 def test_tracer_url_https():
-    t = ddtrace.Tracer()
+    import os
+
+    from ddtrace import tracer as t
+    from ddtrace.profiling import profiler
+    from tests.profiling.test_profiler import _check_url
+
     t.configure(hostname="foobar", https=True)
     prof = profiler.Profiler(tracer=t)
     _check_url(prof, "https://foobar:8126", os.environ.get("DD_API_KEY"))
 
 
+@pytest.mark.subprocess()
 def test_tracer_url_uds_hostname():
-    t = ddtrace.Tracer()
+    import os
+
+    from ddtrace import tracer as t
+    from ddtrace.profiling import profiler
+    from tests.profiling.test_profiler import _check_url
+
     t.configure(hostname="foobar", uds_path="/foobar")
     prof = profiler.Profiler(tracer=t)
     _check_url(prof, "unix://foobar/foobar", os.environ.get("DD_API_KEY"))
 
 
+@pytest.mark.subprocess()
 def test_tracer_url_uds():
-    t = ddtrace.Tracer()
+    import os
+
+    from ddtrace import tracer as t
+    from ddtrace.profiling import profiler
+    from tests.profiling.test_profiler import _check_url
+
     t.configure(uds_path="/foobar")
     prof = profiler.Profiler(tracer=t)
     _check_url(prof, "unix:///foobar", os.environ.get("DD_API_KEY"))
 
 
+@pytest.mark.subprocess()
 def test_tracer_url_configure_after():
-    t = ddtrace.Tracer()
+    import os
+
+    from ddtrace import tracer as t
+    from ddtrace.profiling import profiler
+    from tests.profiling.test_profiler import _check_url
+
     prof = profiler.Profiler(tracer=t)
     t.configure(hostname="foobar")
     _check_url(prof, "http://foobar:8126", os.environ.get("DD_API_KEY"))
@@ -276,11 +306,10 @@ def test_env_no_api_key():
 def test_env_endpoint_url():
     import os
 
-    import ddtrace
+    from ddtrace import tracer as t
     from ddtrace.profiling import profiler
     from tests.profiling.test_profiler import _check_url
 
-    t = ddtrace.Tracer()
     prof = profiler.Profiler(tracer=t)
     _check_url(prof, "http://foobar:123", os.environ.get("DD_API_KEY"))
 
diff --git a/tests/tracer/test_tracer.py b/tests/tracer/test_tracer.py
index 0978e3ae92b..21972d44492 100644
--- a/tests/tracer/test_tracer.py
+++ b/tests/tracer/test_tracer.py
@@ -2106,8 +2106,11 @@ def test_multiple_tracer_instances():
         import ddtrace
 
         assert ddtrace.tracer is not None
-        assert len(warns) == 0
+        for w in warns:
+            # Ensure the warning is not about multiple tracer instances is not logged when importing ddtrace
+            assert "Support for multiple Tracer instances is deprecated" not in str(w.message)
 
+        warns.clear()
         t = ddtrace.Tracer()
         assert t is ddtrace.tracer
         assert len(warns) == 1