diff --git a/api/app/exceptions.py b/api/app/exceptions.py
deleted file mode 100644
index 29452a6f53f2..000000000000
--- a/api/app/exceptions.py
+++ /dev/null
@@ -1,2 +0,0 @@
-class ImproperlyConfiguredError(RuntimeError):
-    pass
diff --git a/api/custom_auth/mfa/trench/responses.py b/api/custom_auth/mfa/trench/responses.py
index 47b9b75467dd..f12e12cf088e 100644
--- a/api/custom_auth/mfa/trench/responses.py
+++ b/api/custom_auth/mfa/trench/responses.py
@@ -4,10 +4,6 @@
 from custom_auth.mfa.trench.exceptions import MFAValidationError
 
 
-class DispatchResponse(Response):
-    _FIELD_DETAILS = "details"
-
-
 class ErrorResponse(Response):
     _FIELD_ERROR = "error"
 
diff --git a/api/custom_auth/oauth/exceptions.py b/api/custom_auth/oauth/exceptions.py
index 150e93e45aec..42eaf1a7a516 100644
--- a/api/custom_auth/oauth/exceptions.py
+++ b/api/custom_auth/oauth/exceptions.py
@@ -4,7 +4,3 @@ class GithubError(Exception):
 
 class GoogleError(Exception):
     pass
-
-
-class OAuthError(Exception):
-    pass
diff --git a/api/environments/identities/serializers.py b/api/environments/identities/serializers.py
index f3e47f42824f..da8708a84dcf 100644
--- a/api/environments/identities/serializers.py
+++ b/api/environments/identities/serializers.py
@@ -6,9 +6,7 @@
 
 from environments.identities.models import Identity
 from environments.models import Environment
-from environments.serializers import EnvironmentSerializerFull
 from features.models import FeatureState
-from features.serializers import FeatureStateSerializerFull
 from util.engine_models.features.models import FeatureStateModel
 
 
@@ -18,15 +16,6 @@ class Meta:
         fields = ("identifier",)
 
 
-class IdentitySerializerFull(serializers.ModelSerializer):  # type: ignore[type-arg]
-    identity_features = FeatureStateSerializerFull(many=True)
-    environment = EnvironmentSerializerFull()
-
-    class Meta:
-        model = Identity
-        fields = ("id", "identifier", "identity_features", "environment")
-
-
 class IdentitySerializer(serializers.ModelSerializer):  # type: ignore[type-arg]
     class Meta:
         model = Identity
diff --git a/api/features/models.py b/api/features/models.py
index c3c557bc5a71..8b590a3eb0fe 100644
--- a/api/features/models.py
+++ b/api/features/models.py
@@ -217,16 +217,6 @@ def _get_project(self) -> typing.Optional["Project"]:
         return self.project
 
 
-def get_next_segment_priority(feature):  # type: ignore[no-untyped-def]
-    feature_segments = FeatureSegment.objects.filter(feature=feature).order_by(
-        "-priority"
-    )
-    if feature_segments.count() == 0:
-        return 1
-    else:
-        return feature_segments.first().priority + 1
-
-
 class FeatureSegment(
     LifecycleModelMixin,  # type: ignore[misc]
     AbstractBaseExportableModel,
diff --git a/api/permissions/serializers.py b/api/permissions/serializers.py
index a0456c4e13d4..70ddbddc3141 100644
--- a/api/permissions/serializers.py
+++ b/api/permissions/serializers.py
@@ -64,11 +64,6 @@ class DerivedFromSerializer(serializers.Serializer):  # type: ignore[type-arg]
     roles = PermissionRoleSerializer(many=True)
 
 
-class BaseDetailedPermissionsSerializer(serializers.Serializer):  # type: ignore[type-arg]
-    is_directly_granted = serializers.BooleanField()
-    derived_from = DerivedFromSerializer()
-
-
 class DetailedPermissionsSerializer(serializers.Serializer):  # type: ignore[type-arg]
     permission_key = serializers.CharField()
     is_directly_granted = serializers.BooleanField()
diff --git a/api/sse/exceptions.py b/api/sse/exceptions.py
index 8dac8276cb72..73ae09ad5770 100644
--- a/api/sse/exceptions.py
+++ b/api/sse/exceptions.py
@@ -1,6 +1,2 @@
 class SSEAuthTokenNotSet(Exception):
     pass
-
-
-class ViewResponseDoesNotHaveStatus(Exception):
-    pass
diff --git a/api/users/models.py b/api/users/models.py
index d1dca609bbc7..1eb067dc95e3 100644
--- a/api/users/models.py
+++ b/api/users/models.py
@@ -20,7 +20,6 @@
 from django_lifecycle.conditions import (  # type: ignore[import-untyped]
     WhenFieldHasChanged,
 )
-from pydantic import BaseModel
 
 from integrations.pylon.identity_verification import get_user_email_signature
 from organisations.models import (
@@ -45,15 +44,6 @@
 from users.constants import DEFAULT_DELETE_ORPHAN_ORGANISATIONS_VALUE
 from users.exceptions import InvalidInviteError
 
-
-class UTMDataModel(BaseModel):
-    utm_source: typing.Optional[str] = None
-    utm_medium: typing.Optional[str] = None
-    utm_campaign: typing.Optional[str] = None
-    utm_term: typing.Optional[str] = None
-    utm_content: typing.Optional[str] = None
-
-
 if typing.TYPE_CHECKING:
     from environments.models import Environment
     from organisations.invites.models import (
diff --git a/api/webhooks/exceptions.py b/api/webhooks/exceptions.py
deleted file mode 100644
index ebc480bc9377..000000000000
--- a/api/webhooks/exceptions.py
+++ /dev/null
@@ -1,2 +0,0 @@
-class WebhookSendError(Exception):
-    pass
diff --git a/api/webhooks/serializers.py b/api/webhooks/serializers.py
index 6623d1e7ab81..bbea56c3e46e 100644
--- a/api/webhooks/serializers.py
+++ b/api/webhooks/serializers.py
@@ -6,10 +6,6 @@ class WebhookSerializer(serializers.Serializer[None]):
     data = serializers.DictField()  # type: ignore[assignment]
 
 
-class WebhookURLSerializer(serializers.Serializer[None]):
-    url = serializers.URLField()
-
-
 class ScopeSerializer(serializers.Serializer[None]):
     type = serializers.ChoiceField(choices=["organisation", "environment"])