diff --git a/corporate/views.py b/corporate/views.py
index 57f6e8d33b..fe1628ac81 100644
--- a/corporate/views.py
+++ b/corporate/views.py
@@ -128,8 +128,8 @@ def upgrade(request: HttpRequest, user: UserProfile,
                 schedule, license_management, licenses, stripe_token is not None,
             )
         return json_error(e.message, data={'error_description': e.description})
-    except Exception as e:
-        billing_logger.exception(f"Uncaught exception in billing: {e}")
+    except Exception:
+        billing_logger.exception("Uncaught exception in billing:")
         error_message = BillingError.CONTACT_SUPPORT
         error_description = "uncaught exception during upgrade"
         return json_error(error_message, data={'error_description': error_description})
diff --git a/puppet/zulip/files/postgresql/process_fts_updates b/puppet/zulip/files/postgresql/process_fts_updates
index d79a6bcc1e..3ede1606d3 100755
--- a/puppet/zulip/files/postgresql/process_fts_updates
+++ b/puppet/zulip/files/postgresql/process_fts_updates
@@ -163,7 +163,7 @@ while True:
         retries -= 1
         if retries <= 0:
             raise
-        logger.info(e)
+        logger.info(e.pgerror, exc_info=True)
         logger.info("Sleeping and reconnecting")
         time.sleep(5)
         if conn is not None:
diff --git a/tools/fetch-contributor-data b/tools/fetch-contributor-data
index 327b921e44..2a258a5466 100755
--- a/tools/fetch-contributor-data
+++ b/tools/fetch-contributor-data
@@ -49,11 +49,8 @@ def fetch_contributors(repo_link: str) -> Optional[List[Dict[str, Dict[str, Any]
 
 def write_to_disk(json_data: ContributorsJSON, out_file: str) -> None:
     with open(out_file, 'w') as f:
-        try:
-            f.write(f"{json.dumps(json_data, indent=2, sort_keys=True)}\n")
-        except OSError as e:
-            logger.warning(e)
-            sys.exit(1)
+        json.dump(json_data, f, indent=2, sort_keys=True)
+        f.write("\n")
 
 def update_contributor_data_file() -> None:
     """
diff --git a/tools/semgrep.yml b/tools/semgrep.yml
index 2841b08f74..fbe63de40f 100644
--- a/tools/semgrep.yml
+++ b/tools/semgrep.yml
@@ -59,9 +59,11 @@ rules:
       - pattern-either:
           - pattern: logging.$Y(... % ...)
           - pattern: logging.$Y(... .format(...))
+          - pattern: logging.$Y(f"...")
           - pattern: logger.$Y(... % ...)
           - pattern: logger.$Y(... .format(...))
-      - pattern-where-python: "vars['$Y'] in ['debug', 'info', 'warning', 'error', 'critical']"
+          - pattern: logger.$Y(f"...")
+      - pattern-where-python: "vars['$Y'] in ['debug', 'info', 'warning', 'error', 'critical', 'exception']"
     severity: ERROR
     message: "Pass format arguments to logging (https://docs.python.org/3/howto/logging.html#optimization)"
 
diff --git a/zerver/data_import/import_util.py b/zerver/data_import/import_util.py
index 3ce3755027..8ef200060d 100644
--- a/zerver/data_import/import_util.py
+++ b/zerver/data_import/import_util.py
@@ -2,7 +2,6 @@ import logging
 import os
 import random
 import shutil
-import traceback
 from typing import AbstractSet, Any, Callable, Dict, Iterable, List, Optional, Set, Tuple, TypeVar
 
 import requests
@@ -586,8 +585,7 @@ def run_parallel_wrapper(f: Callable[[ListJobData], None], full_items: List[List
             try:
                 f(item)
             except Exception:
-                logging.info("Error processing item: %s", item)
-                traceback.print_exc()
+                logging.exception("Error processing item: %s", item)
             count += 1
             if count % 1000 == 0:
                 logging.info("A download thread finished %s items", count)
diff --git a/zerver/lib/actions.py b/zerver/lib/actions.py
index e06ca39475..491eaa3709 100644
--- a/zerver/lib/actions.py
+++ b/zerver/lib/actions.py
@@ -2392,7 +2392,7 @@ def _internal_prep_message(realm: Realm,
         return check_message(sender, get_client("Internal"), addressee,
                              content, realm=realm)
     except JsonableError as e:
-        logging.exception(f"Error queueing internal message by {sender.delivery_email}: {e}")
+        logging.exception("Error queueing internal message by %s: %s", sender.delivery_email, e.msg)
 
     return None
 
diff --git a/zerver/lib/bugdown/__init__.py b/zerver/lib/bugdown/__init__.py
index 5bb48f9a90..779ee17d70 100644
--- a/zerver/lib/bugdown/__init__.py
+++ b/zerver/lib/bugdown/__init__.py
@@ -6,7 +6,6 @@ import logging
 import os
 import re
 import time
-import traceback
 import urllib
 import urllib.parse
 from collections import defaultdict, deque
@@ -424,7 +423,7 @@ def fetch_tweet_data(tweet_id: str) -> Optional[Dict[str, Any]]:
                 # but for now it seems reasonable to log at error
                 # level (so that we get notified), but then cache the
                 # failure to proceed with our usual work
-                bugdown_logger.error(traceback.format_exc())
+                bugdown_logger.exception("Unknown error fetching tweet data")
                 return None
     return res
 
@@ -984,7 +983,7 @@ class InlineInterestingLinkProcessor(markdown.treeprocessors.Treeprocessor):
             # We put this in its own try-except because it requires external
             # connectivity. If Twitter flakes out, we don't want to not-render
             # the entire message; we just want to not show the Twitter preview.
-            bugdown_logger.warning(traceback.format_exc())
+            bugdown_logger.warning("Error building Twitter link", exc_info=True)
             return None
 
     def get_url_data(self, e: Element) -> Optional[Tuple[str, Optional[str]]]:
@@ -2367,9 +2366,11 @@ def do_convert(content: str,
         # NOTE: Don't change this message without also changing the
         # logic in logging_handlers.py or we can create recursive
         # exceptions.
-        exception_message = ('Exception in Markdown parser: %sInput (sanitized) was: %s\n (message %s)'
-                             % (traceback.format_exc(), cleaned, logging_message_id))
-        bugdown_logger.exception(exception_message)
+        bugdown_logger.exception(
+            'Exception in Markdown parser; input (sanitized) was: %s\n (message %s)',
+            cleaned,
+            logging_message_id,
+        )
 
         raise BugdownRenderingException()
     finally:
diff --git a/zerver/lib/email_mirror.py b/zerver/lib/email_mirror.py
index bc8765b32d..0344f106aa 100644
--- a/zerver/lib/email_mirror.py
+++ b/zerver/lib/email_mirror.py
@@ -408,12 +408,11 @@ def process_message(message: EmailMessage, rcpt_to: Optional[str]=None) -> None:
             process_missed_message(to, message)
         else:
             process_stream_message(to, message)
+    except ZulipEmailForwardUserError as e:
+        # TODO: notify sender of error, retry if appropriate.
+        logging.warning(e.args[0])
     except ZulipEmailForwardError as e:
-        if isinstance(e, ZulipEmailForwardUserError):
-            # TODO: notify sender of error, retry if appropriate.
-            logging.warning(str(e))
-        else:
-            log_and_report(message, str(e), to)
+        log_and_report(message, e.args[0], to)
 
 def validate_to_address(rcpt_to: str) -> None:
     if is_missed_message_address(rcpt_to):
diff --git a/zerver/lib/outgoing_webhook.py b/zerver/lib/outgoing_webhook.py
index bfcc7e2ac9..6c74734c59 100644
--- a/zerver/lib/outgoing_webhook.py
+++ b/zerver/lib/outgoing_webhook.py
@@ -332,6 +332,6 @@ def do_rest_call(base_url: str,
         response_message = ("An exception of type *%s* occurred for message `%s`! "
                             "See the Zulip server logs for more information." % (
                                 type(e).__name__, event["command"]))
-        logging.exception(f"Outhook trigger failed:\n {e}")
+        logging.exception("Outhook trigger failed:")
         fail_with_message(event, response_message)
         notify_bot_owner(event, exception=e)
diff --git a/zerver/lib/push_notifications.py b/zerver/lib/push_notifications.py
index 1029eab664..bc255d6b82 100644
--- a/zerver/lib/push_notifications.py
+++ b/zerver/lib/push_notifications.py
@@ -279,8 +279,8 @@ def send_android_push_notification(devices: List[DeviceToken], data: Dict[str, A
                                       priority=priority,
                                       data=data,
                                       retries=10)
-    except OSError as e:
-        logger.warning(str(e))
+    except OSError:
+        logger.warning("Error while pushing to GCM", exc_info=True)
         return
 
     if res and 'success' in res:
diff --git a/zerver/lib/queue.py b/zerver/lib/queue.py
index e5d5489598..56f7f31ec1 100644
--- a/zerver/lib/queue.py
+++ b/zerver/lib/queue.py
@@ -194,9 +194,9 @@ class ExceptionFreeTornadoConnection(pika.adapters.tornado_connection.TornadoCon
             super()._adapter_disconnect()
         except (pika.exceptions.ProbableAuthenticationError,
                 pika.exceptions.ProbableAccessDeniedError,
-                pika.exceptions.IncompatibleProtocolError) as e:
-            logging.warning("Caught exception '%r' in ExceptionFreeTornadoConnection when \
-calling _adapter_disconnect, ignoring", e)
+                pika.exceptions.IncompatibleProtocolError):
+            logging.warning("Caught exception in ExceptionFreeTornadoConnection when \
+calling _adapter_disconnect, ignoring", exc_info=True)
 
 
 class TornadoQueueClient(SimpleQueueClient):
diff --git a/zerver/lib/sessions.py b/zerver/lib/sessions.py
index 63422aadcb..5c4265654d 100644
--- a/zerver/lib/sessions.py
+++ b/zerver/lib/sessions.py
@@ -67,8 +67,8 @@ def get_expirable_session_var(session: Session, var_name: str, default_value: An
 
     try:
         value, expire_at = (session[var_name]['value'], session[var_name]['expire_at'])
-    except (KeyError, TypeError) as e:
-        logging.warning("get_expirable_session_var: Variable %s: %s", var_name, e)
+    except (KeyError, TypeError):
+        logging.warning("get_expirable_session_var: error getting %s", var_name, exc_info=True)
         return default_value
 
     if timestamp_to_datetime(expire_at) < timezone_now():
diff --git a/zerver/management/commands/sync_ldap_user_data.py b/zerver/management/commands/sync_ldap_user_data.py
index a539b8422e..ad8874b0bf 100644
--- a/zerver/management/commands/sync_ldap_user_data.py
+++ b/zerver/management/commands/sync_ldap_user_data.py
@@ -27,7 +27,7 @@ def sync_ldap_user_data(user_profiles: List[UserProfile], deactivation_protectio
                 sync_user_from_ldap(u, logger)
             except ZulipLDAPException as e:
                 logger.error("Error attempting to update user %s:", u.delivery_email)
-                logger.error(e)
+                logger.error(e.args[0])
 
         if deactivation_protection:
             if not UserProfile.objects.filter(is_bot=False, is_active=True).exists():
diff --git a/zerver/tests/test_messages.py b/zerver/tests/test_messages.py
index 8928ad3df7..1ee2f3718f 100644
--- a/zerver/tests/test_messages.py
+++ b/zerver/tests/test_messages.py
@@ -538,8 +538,11 @@ class InternalPrepTest(ZulipTestCase):
                 content=bad_content,
             )
 
-        arg = m.call_args_list[0][0][0]
-        self.assertIn('Message must not be empty', arg)
+        m.assert_called_once_with(
+            "Error queueing internal message by %s: %s",
+            "cordelia@zulip.com",
+            "Message must not be empty",
+        )
 
         with mock.patch('logging.exception') as m:
             internal_send_huddle_message(
@@ -549,8 +552,11 @@ class InternalPrepTest(ZulipTestCase):
                 content=bad_content,
             )
 
-        arg = m.call_args_list[0][0][0]
-        self.assertIn('Message must not be empty', arg)
+        m.assert_called_once_with(
+            "Error queueing internal message by %s: %s",
+            "cordelia@zulip.com",
+            "Message must not be empty",
+        )
 
         with mock.patch('logging.exception') as m:
             internal_send_stream_message(
@@ -561,8 +567,11 @@ class InternalPrepTest(ZulipTestCase):
                 stream=stream,
             )
 
-        arg = m.call_args_list[0][0][0]
-        self.assertIn('Message must not be empty', arg)
+        m.assert_called_once_with(
+            "Error queueing internal message by %s: %s",
+            "cordelia@zulip.com",
+            "Message must not be empty",
+        )
 
         with mock.patch('logging.exception') as m:
             internal_send_stream_message_by_name(
@@ -573,8 +582,11 @@ class InternalPrepTest(ZulipTestCase):
                 content=bad_content,
             )
 
-        arg = m.call_args_list[0][0][0]
-        self.assertIn('Message must not be empty', arg)
+        m.assert_called_once_with(
+            "Error queueing internal message by %s: %s",
+            "cordelia@zulip.com",
+            "Message must not be empty",
+        )
 
     def test_error_handling(self) -> None:
         realm = get_realm('zulip')
@@ -606,9 +618,11 @@ class InternalPrepTest(ZulipTestCase):
                 sender=sender,
                 recipient_user=recipient_user,
                 content=content)
-        arg = logging_mock.call_args_list[0][0][0]
-        prefix = "Error queueing internal message by cordelia@zulip.com: You can't send private messages outside of your organization."
-        self.assertTrue(arg.startswith(prefix))
+        logging_mock.assert_called_once_with(
+            "Error queueing internal message by %s: %s",
+            "cordelia@zulip.com",
+            "You can't send private messages outside of your organization.",
+        )
 
     def test_ensure_stream_gets_called(self) -> None:
         realm = get_realm('zulip')
diff --git a/zerver/tests/test_push_notifications.py b/zerver/tests/test_push_notifications.py
index 6255fbc1db..0cc191112e 100644
--- a/zerver/tests/test_push_notifications.py
+++ b/zerver/tests/test_push_notifications.py
@@ -1654,7 +1654,7 @@ class GCMSendTest(PushNotificationTest):
                                          mock_gcm: mock.MagicMock) -> None:
         mock_gcm.json_request.side_effect = IOError('error')
         send_android_push_notification_to_user(self.user_profile, {}, {})
-        mock_warn.assert_called_with('error')
+        mock_warn.assert_called_with("Error while pushing to GCM", exc_info=True)
 
     @mock.patch('zerver.lib.push_notifications.logger.warning')
     @mock.patch('zerver.lib.push_notifications.logger.info')
diff --git a/zerver/tests/test_queue_worker.py b/zerver/tests/test_queue_worker.py
index 241093c30d..599fb09f31 100644
--- a/zerver/tests/test_queue_worker.py
+++ b/zerver/tests/test_queue_worker.py
@@ -548,7 +548,8 @@ class WorkerTest(ZulipTestCase):
             with patch('logging.exception') as logging_exception_mock:
                 worker.start()
                 logging_exception_mock.assert_called_once_with(
-                    "Problem handling data on queue unreliable_worker")
+                    "Problem handling data on queue %s", "unreliable_worker",
+                )
 
         self.assertEqual(processed, ['good', 'fine', 'back to normal'])
         with open(fn) as f:
@@ -586,7 +587,8 @@ class WorkerTest(ZulipTestCase):
                 except AbortLoop:
                     pass
                 logging_exception_mock.assert_called_once_with(
-                    "Problem handling data on queue unreliable_loopworker")
+                    "Problem handling data on queue %s", "unreliable_loopworker",
+                )
 
         self.assertEqual(processed, ['good', 'fine'])
         with open(fn) as f:
diff --git a/zerver/tornado/event_queue.py b/zerver/tornado/event_queue.py
index 6fe5b0de80..edcea98685 100644
--- a/zerver/tornado/event_queue.py
+++ b/zerver/tornado/event_queue.py
@@ -489,14 +489,14 @@ def load_event_queues(port: int) -> None:
     except FileNotFoundError:
         pass
     except ValueError:
-        logging.exception("Tornado %d could not deserialize event queues" % (port,))
+        logging.exception("Tornado %d could not deserialize event queues", port)
     else:
         try:
             clients = {
                 qid: ClientDescriptor.from_dict(client) for (qid, client) in data
             }
         except Exception:
-            logging.exception("Tornado %d could not deserialize event queues" % (port,))
+            logging.exception("Tornado %d could not deserialize event queues", port)
 
     for client in clients.values():
         # Put code for migrations due to event queue data format changes here
diff --git a/zerver/worker/queue_processors.py b/zerver/worker/queue_processors.py
index cd31dffc43..e3a4ee8af0 100644
--- a/zerver/worker/queue_processors.py
+++ b/zerver/worker/queue_processors.py
@@ -148,7 +148,7 @@ def retry_send_email_failures(
             func(worker, data)
         except (smtplib.SMTPServerDisconnected, socket.gaierror, EmailNotDeliveredException):
             def on_failure(event: Dict[str, Any]) -> None:
-                logging.exception(f"Event {event} failed")
+                logging.exception("Event %r failed", event)
 
             retry_event(worker.queue_name, data, on_failure)
 
@@ -256,7 +256,7 @@ class QueueProcessingWorker(ABC):
         check_and_send_restart_signal()
 
     def _log_problem(self) -> None:
-        logging.exception(f"Problem handling data on queue {self.queue_name}")
+        logging.exception("Problem handling data on queue %s", self.queue_name)
 
     def setup(self) -> None:
         self.q = SimpleQueueClient()
diff --git a/zproject/backends.py b/zproject/backends.py
index 13bdffa005..4b22b1f6e7 100644
--- a/zproject/backends.py
+++ b/zproject/backends.py
@@ -1397,7 +1397,7 @@ class SocialAuthMixin(ZulipAuthMixin, ExternalAuthMethod):
             # the flow or the IdP is unreliable and returns a bad http response),
             # don't throw a 500, just send them back to the
             # login page and record the event at the info log level.
-            self.logger.info(f"{e.__class__.__name__}: {str(e)}")
+            self.logger.info("%s: %s", e.__class__.__name__, str(e))
             return None
         except SocialAuthBaseException as e:
             # Other python-social-auth exceptions are likely
@@ -1813,9 +1813,9 @@ class SAMLAuthBackend(SocialAuthMixin, SAMLAuth):
         try:
             resp = OneLogin_Saml2_Response(settings={}, response=SAMLResponse)
             issuers = resp.get_issuers()
-        except cls.SAMLRESPONSE_PARSING_EXCEPTIONS as e:
+        except cls.SAMLRESPONSE_PARSING_EXCEPTIONS:
             logger = logging.getLogger(f"zulip.auth.{cls.name}")
-            logger.info("Error while parsing SAMLResponse: %s: %s", e.__class__.__name__, e)
+            logger.info("Error while parsing SAMLResponse:", exc_info=True)
             return None
 
         for idp_name, idp_config in settings.SOCIAL_AUTH_SAML_ENABLED_IDPS.items():
@@ -1920,9 +1920,9 @@ class SAMLAuthBackend(SocialAuthMixin, SAMLAuth):
 
             # Call the auth_complete method of SocialAuthMixIn
             result = super().auth_complete(*args, **kwargs)
-        except self.SAMLRESPONSE_PARSING_EXCEPTIONS as e:
+        except self.SAMLRESPONSE_PARSING_EXCEPTIONS:
             # These can be raised if SAMLResponse is missing or badly formatted.
-            self.logger.info("/complete/saml/: %s: %s", e.__class__.__name__, e)
+            self.logger.info("/complete/saml/: error while parsing SAMLResponse:", exc_info=True)
             # Fall through to returning None.
         finally:
             if result is None:
diff --git a/zproject/wsgi.py b/zproject/wsgi.py
index 75144d5732..293aa38cec 100644
--- a/zproject/wsgi.py
+++ b/zproject/wsgi.py
@@ -28,7 +28,7 @@ import django
 
 try:
     django.setup()
-except Exception as e:
+except Exception:
     # If /etc/zulip/settings.py contains invalid syntax, Django
     # initialization will fail in django.setup().  In this case, our
     # normal configuration to logs errors to /var/log/zulip/errors.log
@@ -39,7 +39,7 @@ except Exception as e:
     logging.basicConfig(filename='/var/log/zulip/errors.log', level=logging.INFO,
                         format='%(asctime)s %(levelname)s %(name)s %(message)s')
     logger = logging.getLogger(__name__)
-    logger.exception(e)
+    logger.exception("django.setup() failed:")
     raise
 
 # Because import_module does not correctly handle safe circular imports we